<h4>Abstract</h4>Strong or weak, light or dark, black or with cream; everyone who drinks coffee has a preference. Today, there are not only the choices of what you would like in your coffee, but also how you would like it brewed. Do you prefer the old fashioned percolator or the straight forward brewed coffee? Or do you like the new coffee by the cup makers or the instant coffees? There are so many options! This study will analyze four different instant coffee blends for some of their respective flavors using a purge and trap concentrator.<h4>Discussion</h4>Most of us who drink coffee know our preferences. We know which blend we like, what strength and definitely what we like in our coffee. However, most of us do not think about the flavors that go into our coffee that help us define our preferences. Coffee manufacturers, on the other hand, are working diligently to create a new blend or a more satisfying flavor that would make us want to choose their coffee over another maker.This study will look at four different blends of coffee and some of the compounds that contribute to the flavor of the blend. Using purge and trap sampling, the flavor compounds were purged out of the coffee and trapped onto an adsorbent trap. The analytes were then transferred to a Gas Chromatograph/Mass Spectrometer (GC/MS) for analysis. The study focused on six flavor compounds: the spicy smoky aroma of 2-methylfuran, the spicy caramel, almond odor of 5-methylfurfural, the buttery scent provided by the addition of 2,3-butanedione and 2,3-pentanedione, and the impact of the two and three methyl butanals giving the dark chocolate malty flavor to the coffee.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/EST_Analytical_Purge_and_Trap_Analysis_of_Coffee_Flavors_by_Purge_and_Trap_Sampling_ca25beef60_1_acf9fc0b4f.jpg" alt="EST Analytical: Encon Evolution Purge and Trap Concentrator and Centurion WS Autosampler" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_EST_Analytical_Purge_and_Trap_Analysis_of_Coffee_Flavors_by_Purge_and_Trap_Sampling_ca25beef60_1_acf9fc0b4f.jpg 197w," sizes="100vw" width="668" height="531"><h4>Experimental</h4>The EST Analytical <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/2160">Encon Evolution Purge and Trap Concentrator</a> and <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/2159">Centurion WS Autosampler</a> were interfaced to a GC/MS. The Centurion WS was run in the soil mode and the purge and trap concentrator was configured with a Vocarb 3000 (K) analytical trap. The column selected for this study was an Rtx-1 60 m × 0.25 mm × 1 µm. Sampling method parameters and GC/MS parameters are listed below.<h5>Purge and Trap Parameters</h5><ul><li>Concentrator: EST Encon Evolution</li><li>Trap type: Vocarb 3000</li><li>Valve oven temperature: 150 °C</li><li>Transfer line temperature: 150 °C</li><li>Trap temperature: 35 °C</li><li>Moisture Reduction Trap (MoRT) temperature: 39 °C</li><li>Purge time: 11 min</li><li>Purge flow: 40 mL/min</li><li>Dry purge Temp.: Ambient</li><li>Dry Purge Flow: 50mL/min</li><li>Dry Purge Time: 1.0 min &nbsp;</li><li>Desorb pressure Control: ON</li><li>Desorb Pressure: 5psi</li><li>Desorb time: 0.5 min</li><li>Desorb preheat delay: 5 sec</li><li>Desorb temperature: 260 °C</li><li>MoRT bake temperature: 230 °C</li><li>Bake temperature: 260 °C</li><li>Sparge vessel bake temperature: 120 °C</li><li>Bake time: 8 min</li><li>Bake flow: 85 mL/min</li></ul><h5>Auto-Sampler (EST Centurion WS):</h5><ul><li>Sample type: Soil</li><li>Sample Fill Mode: loop</li><li>Sample Volume: 10mL</li><li>Sample Prime Time: 5 sec</li><li>Loop Equilibration Time: 10 sec</li><li>Sample Transfer Time: 15 sec</li><li>Sample Loop Rinse: Off</li><li>Sample Loop Sweep Time: 15 sec</li><li>Number of Sparge Rinses: 1</li><li>Rinse Volume: 5mL</li><li>Rinse Transfer Time: 20 sec</li><li>Rinse Drain Time: 20 sec</li><li>Number of Foam Rinse Cycles: 1</li><li>Water Heater Temp.: 85°C</li><li>Sample Preheat Temp.: 40°C</li><li>Soil Valve Temp.: 85°C</li><li>Soil Transfer Line Temp.: 150°C &nbsp;</li></ul><h5>GC/MS Parameters</h5><ul><li>System: <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=10&amp;search=7890%2F5975">Agilent 7890/5975</a></li><li>Inlet: Split mode, 200 °C, 20:1 split ratio, 16.041 psi head pressure</li><li>Column: Rtx-1 60m x 0.25mm I.D. 1.0µm film thickness</li><li>Oven program: 35 °C (1 min) → ramp 4 °C/min → 230 °C, total run time of 49.75 min</li><li>Column flow rate: 1 mL/min helium</li><li>Total flow: 26.0 mL/min</li><li>Source temperature: 230 °C</li><li>Quadrupole temperature: 150 °C</li><li>Transfer line temperature: 180 °C</li><li>Scan range: m/z 35–265, 3.12 scans/sec</li><li>Solvent delay: 0.0 min</li></ul>The GC column was acquired from Restek while the instant coffees were purchased at a local retailer. The four roasts chosen for this study ranged from light to dark. One half of a gram of each coffee was dissolved in 40 mL of de-ionized water at room temperature. The vials were shaken in order to fully dissolve the coffee. Next, 5 mL of each coffee mixture were run in the soil mode using the Centurion WS autosampler and the Encon Evolution purge and trap concentrator. Each coffee was run in triplicate in order to verify the results. Figures 1 through 3 display a bar graph comparison of the flavors in each coffee blend. Chromatograms of the coffee blends are shown in Figures 4 through 7.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/EST_Analaytical_Figure_1_Buttery_Compound_Comparison_08f6fd5d05.jpg" alt="EST Analytical: Figure 1 Buttery Compound Comparison" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_EST_Analaytical_Figure_1_Buttery_Compound_Comparison_08f6fd5d05.jpg 245w," sizes="100vw" width="905" height="544"><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/EST_Analaytical_Figure_2_Smoky_and_Spicy_Caramel_Compound_Comparison_6940d35e36.jpg" alt="EST Analytical: Figure 2 Smoky and Spicy Caramel Compound Comparison" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_EST_Analaytical_Figure_2_Smoky_and_Spicy_Caramel_Compound_Comparison_6940d35e36.jpg 245w," sizes="100vw" width="905" height="545"><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/EST_Analaytical_Figure_3_Dark_Chocolate_Malty_Compound_Comparison_cbee579baf.jpg" alt="EST Analytical: Figure 3 Dark Chocolate - Malty Compound Comparison" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_EST_Analaytical_Figure_3_Dark_Chocolate_Malty_Compound_Comparison_cbee579baf.jpg 245w," sizes="100vw" width="905" height="545"><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/EST_Analaytical_Figure_4_Light_Roast_Chromatogram_8380d110a6.jpg" alt="EST Analytical: Figure 4 Light Roast Chromatogram" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_EST_Analaytical_Figure_4_Light_Roast_Chromatogram_8380d110a6.jpg 245w," sizes="100vw" width="953" height="375"><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/EST_Analaytical_Figure_5_Medium_Roast_Chromatogram_9a97a58a74.jpg" alt="EST Analytical: Figure 5 Medium Roast Chromatogram" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_EST_Analaytical_Figure_5_Medium_Roast_Chromatogram_9a97a58a74.jpg 245w," sizes="100vw" width="886" height="401"><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/EST_Analaytical_Figure_6_Medium_Dark_Roast_Chromatogram_eb6a37cd16.jpg" alt="EST Analytical: Figure 6 Medium Dark Roast Chromatogram" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_EST_Analaytical_Figure_6_Medium_Dark_Roast_Chromatogram_eb6a37cd16.jpg 245w," sizes="100vw" width="877" height="410"><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/EST_Analaytical_Figure_7_Dark_Roast_Chromatogram_79711f7858.jpg" alt="EST Analytical: Figure 7 Dark Roast Chromatogram" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_EST_Analaytical_Figure_7_Dark_Roast_Chromatogram_79711f7858.jpg 245w," sizes="100vw" width="856" height="412"><h4>Conclusion</h4>The lightest roast had the most buttery and dark chocolate/malty flavors while the darkest roast had more of the smoky flavor. Surprisingly, the darkest roast and the medium roast had similar proportions of the flavor compounds with the exception of the smoky flavor. While the light roast had large amounts of the flavors tested for, the chromatography of the light roast was much simpler than that of the darker roasts. Overall, the Encon Evolution Purge and Trap Concentrator in conjunction with the Centurion WS Autosampler proved to be an excellent system for sampling coffee. The results were reproducible and provided a lot of information on the flavors of the respective coffees.

Analysis of Coffee Flavors by Purge and Trap Sampling

News from LabRulezGCMS Library - Week 44, 2025

Our Library never stops expanding. What are the most recent contributions to LabRulezGCMS Library in the week of 3rd November 2025? Check out new documents from the field of the gas phase, especially GC and GC/MS techniques!<blockquote>👉 <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library">SEARCH THE LARGEST REPOSITORY OF DOCUMENTS ABOUT GCMS AND RELATED TECHNIQUES</a></blockquote><blockquote>👉 Need info about different analytical techniques? Peek into <a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/library">LabRulezLCMS</a> or <a target="_blank" rel="noopener noreferrer" href="https://icpms.labrulez.com/library">LabRulezICPMS</a> libraries.</blockquote>This week we bring you applicaton notes by Agilent Technologies, EST Analytical and Thermo Fisher Scientific and poster by Shimadzu!<h3>1. Agilent Technologies: Estimation of Methyl Bromide Residues in Food</h3>Using the Agilent 8890 GC and Agilent 7010 triple quadrupole GC/MS system with Agilent 8697 headspace sampler<ul><li>Application note</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/labrulez-bucket-strapi-h3hsga3/an_methyl_bromide_food_8890_gc_7010_tq_8697_hs_5994_8499en_agilent_35c0751a37.pdf">Full PDF for download</a></li></ul>Bromomethane (methyl bromide) is a halogenated hydrocarbon with a boiling point of 3.6 °C. It is widely used as a fumigant due to its strong fumigation and penetration effects, effectively controlling pests.1 However, methyl bromide is harmful to the ozone layer, causes environmental pollution, and is harmful to humans.2 By 2015, most countries phased out its production and application, except for essential uses such as port quarantine. China stopped agricultural use of methyl bromide by the end of 2018.2 Despite its high volatility, residues of methyl bromide can persist in foods such as nuts and seeds. Therefore, quantitative methods for determining these residues are important. Gas chromatography (GC) is commonly used for analysis, either directly with headspace sampling, or with sample pretreatment methods including solvent extraction and solid phase microextraction. Various detectors are used with GC, such as the flame ionization detector, electron capture detector, and electron ionization. Detection can also be performed by mass spectrometer, using an electron ionization (EI) source. The maximum residue limit for methyl bromide in the EU is 10&nbsp;ng/g, according to EU Regulation number 396/2005.&nbsp;In this application note, an <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=1-10&amp;search=8697+headspace+">Agilent 8697 headspace sampler</a> was used for sample introduction to an <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=1-10&amp;search=8890">Agilent 8890 GC system</a> coupled with an <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=10&amp;search=7010">Agilent 7010 triple quadrupole GC/MS</a> for quantification of methyl bromide residues.<h4>Results and discussion&nbsp;</h4><h5>Calibration&nbsp;</h5>Figures 1 through 3 show the linearity of the methyl bromide calibration curve in rice, cumin powder, and red chili powder, respectively. The R2 obtained was above 0.998.&nbsp;<h5>Repeatability&nbsp;</h5>The repeatability of this method was demonstrated by injecting six replicates of rice, cumin, and red chili powder spiked with 10 ng/g of methyl bromide. The area %RSD and retention time %RSD results are shown in Table 3.&nbsp;<h5>Recovery&nbsp;</h5>Methyl bromide was spiked in samples of rice, cumin, and red chili powder at concentration levels of 10 ng/g. Acceptable recoveries were obtained by quantification through prespike matrix-based calibration. Results are highlighted in Table 4.<h4>Conclusion&nbsp;</h4>An accurate and rugged method was developed which meets the requirements of the EURL for the maximum residue limit of methyl bromide in foodstuffs. This ranges from 10 to 100 ng/g, depending on the commodity (Reg. (EC) number 396/2005) for the analysis of pesticides in rice, cumin powder, and red chili powder. The LOQ of the method was demonstrated at 5 ng/g for all tested matrices. Repeatable results were found for six successive replicates of matrix‑based standards at 10 ng/g concentration levels. Sufficient recoveries were obtained in all tested matrices at 10 ng/g spiked concentration levels. Thus, this study demonstrates the applicability of this method for routine analysis of food samples for methyl bromide at trace levels.<h3>2. EST Analytical: Effect of Split Ratio on USEPA Method 8260 Compounds</h3><ul><li>Application note</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/labrulez-bucket-strapi-h3hsga3/Purge_and_Trap_Effect_Split_Ratio_on_USEPA_8260_Compounds_2b7339c7c7.pdf">Full PDF for download</a></li></ul>Injection size on a GC column is dictated by the diameter of the GC column. Packed columns are usually shorter in length and larger in diameter and are usually filled with a packing coated with stationary phase. Due to their large diameter, packed columns can handle much larger injections. However, since packed columns are shorter in length, compound resolution is more difficult. Capillary columns, on the other hand, are much longer with much smaller diameters. A capillary column has a stationary phase that is coated onto the column wall which in turn makes the diameter even smaller. Overloading is a common problem with capillary columns, thus smaller injections and higher dilutions are required when using a capillary column.&nbsp;The benefit of a capillary column is that it has substantially more theoretical plates than a packed column. Increasing the number of theoretical plates enhances column efficiency because peaks are narrowed and peak resolution is improved. The disadvantage of the capillary column is column overloading. This is where a split injection is greatly beneficial. A split injection can limit sample overload while taking advantage of the efficiency of the capillary column.&nbsp;<h4>Discussion:&nbsp;</h4>Purge and trap sampling is the method used for purging volatile compounds out of a water matrix for USEPA Method 8260. Due to the large number of analytes and the lower detection limits required in this method, a capillary column is needed for detection and separation. Split injections provide a method to control moisture from the purge and trap sampling while preventing column overloading with the capillary column. However, due to the detection limits required of the method, if the split injection is too large, the detection limits of the method may not be met. On the other hand, if the split injection is too small, there can be moisture problems with the mass spectrometer. This application will provide a comparison of several different split rates and their effect on compound detection for USEPA Method 8260.<h4>Experimental:&nbsp;</h4>The sampling system used for this study was the <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/2160">EST Analytical Evolution concentrator</a> and the <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/2159">Centurion WS autosampler</a>. The concentrator was affixed with a Vocarb 3000 trap and connected to an <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=1-10&amp;search=7890A">Agilent 7890A GC</a> and <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=1-10&amp;search=5975C">5975C </a>inert XL MS. The GC was configured with a Restek Rxi-624 Sil MS 30m x 0.25mm x 1.4µm column. Three different split ratios were used for this study. Refer to Table 1 for the sampling method parameters and Table 2 for GC/MS parameters.<h4>Conclusions:&nbsp;</h4>As USEPA Methods require lower and lower detection limits, split ratios will play a large factor in reaching these new requirements. This study demonstrated that all three split ratios met USEPA Method 8260 requirements for linearity, compound response and method detection limits. However, there was a remarkable difference in compound detection limits as the split ratio was increased. The 40 to 1 split rate had much lower detection limits due to an increase in compound response. The Encon Evolution purge and trap concentrator has a unique feature for moisture control using an eight port valve to avoid desorbing through the moisture trap. This feature enables better moisture control when using a lower split rate, thus using a larger split rate to control moisture is unnecessary.<h3>3. Shimadzu / AOAC: Simultaneous analysis of residual contaminants in drinking water using Programmed Temperature Vaporization (PTV) for Large Volume Injection (LVI) and GC-MS/MS</h3><ul><li>Poster</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/labrulez-bucket-strapi-h3hsga3/aoac_2025_w016_04bda0b617.pdf">Full PDF for download</a></li></ul>This study aimed to develop a single analytical method for the simultaneous analysis of over 60 residual contaminants, including Poly-Aromatic Hydrocarbons (PAH), Poly-Chlorinated Biphenyls (PCB), and pesticides, in drinking water. Traditionally, multiple methods are being employed for analyzing these contaminants. Most common ones include, extraction using solvents in large separating funnel or SPE cartridge followed by volume concentration by evaporation. These methods require huge sample and solvent quantities. Due to these factors like large sample size handling, concentration steps etc., method may show poor reproducibility.&nbsp;By utilizing Programmed Temperature Vaporization (PTV) for Large Volume Injection (LVI), the method significantly reduces the initial sample amount required for preparation, pre-treatment steps, and solvent consumption compared to conventional approaches, while eliminating the need for final sample concentration. The optimized procedure achieved limits of quantification (LOQs) as low as 0.005 ppb and 0.05 ppb, demonstrating high sensitivity without compromising efficiency. Validation parameters like specificity, linearity, recovery and precision were studied as per SANTE guidelines[1] . For linearity and recovery study, matrix match calibration was used.<h4>Materials and methods&nbsp;</h4>For this study, reference standard mixtures of over 60 contaminants regulated in drinking water were procured from Restek® Corporation. It included PAH, PCB and GC amenable pesticides. Drinking water sample was extracted and used to prepare matrix-matched calibration standards and spiked samples. This method was validated for criteria mentioned in SANTE Guidelines. <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=1&amp;search=GCMS-TQ8040+NX">GCMS-TQ8040 NX</a> (Figure 2), manufactured by Shimadzu Corporation Japan, was used to quantify residual contaminants in drinking water sample.<h4>Conclusion</h4><ul><li>This study shows that the extraction of reduced sample quantity combined with LVI of 50 μL on GC-MS/MS system is a reliable and efficient tool to simultaneously quantify residual contaminants like PAH, PCB and pesticides in drinking water sample.</li><li>Also, highly sensitive Shimadzu GC-MS/MS allows trace level detection even without the need of evaporating &amp; concentrating the sample. This helps in ruggedness resulting in reproducible detection of analytes.</li><li>The combination of sensitive instrument and reproducible extraction method enables its use in testing laboratories for residual contaminants analysis in drinking water.</li></ul><h3>4. Thermo Fisher Scientific: Automated liquid-liquid extraction workflow for direct ultra-trace analysis of pesticides and PAHs in water matrices using GC-MS/MS</h3><ul><li>Application note</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/labrulez-bucket-strapi-h3hsga3/an_003943_gc_autosampler_triplus_rsh_smart_environmental_an003943_na_en_b9980f4e3e.pdf">Full PDF for download</a></li></ul>Ensuring high standards of water quality is a fundamental priority within the European Union. This is highlighted through stringent EU regulations, such as the Water Framework Directive and the Drinking Water Directive,1 where protection of the environment and safeguarding public health are of utmost importance. As such, regular monitoring of both surface and drinking water for hazardous semi-volatile organic compounds, such as polyaromatic hydrocarbons (PAHs) and pesticides, is needed.1,2&nbsp;To meet regulatory compliance, laboratories are required to reach ultra-trace levels (i.e., parts per-trillion (ng/L)), while maintaining analytical method performance criteria outlined under EU Directive 2020/2184.3 To reach required concentration limits, laboratories typically need to extract large sample volumes using solvent (i.e., liquid-liquid) or sorbent-based (i.e., solid-phase) extraction techniques with additional preconcentration.Such techniques involve manual operations, which are costly in terms of consumables and time. However, automated sample preparation and extraction can reduce such costs while helping to eliminate systematic errors to improve data quality and lab efficiency.&nbsp;The aim of this work was to evaluate the sensitivity, precision, and robustness of the TriPlus RSH SMART autosampler in performing automated liquid-liquid extraction and on-line analysis of polyaromatic hydrocarbons (PAHs) and pesticides in drinking and surface water using triple quadrupole GC-MS/MS. This study will demonstrate that the developed automated workflow is compliant with EU regulation criteria and greatly increases laboratory productivity by reducing laboratory costs and time.<h4>Experimental</h4><h5>Instrument and method setup&nbsp;</h5>A <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/486">Thermo Scientific™ TRACE™ 1610 GC </a>equipped with a <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/1744">Thermo Scientific™ TraceGOLD™ TG5-SilMS</a> (30 m × 0.25 mm I.D. × 0.25 µm film) capillary column with a 5 m integrated SafeGuard retention gap (P/N 26096-1425) was used to perform the chromatographic separation. The <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/422">TriPlus RSH SMART autosampler</a> was configured to perform automated sample preparation, liquid-liquid extraction, and on-line injection for GC-MS/MS analysis. The automated workflow was designed using the Thermo Scientific™ TriPlus™ RSH Sampling Workflow Editor Software (P/N 1R77010-1200) and imported into the <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/76">Thermo Scientific™ Chromeleon™ 7.3.2 Chromatography Data System (CDS) software</a>. This integration allows sample preparation, acquisition, and data processing to be carried out within a single software. The automated workflow involved the following steps: internal standard addition, extraction solvent addition (pentane) and vortexing for extraction, addition of solvent for emulsion removal (isopropyl alcohol), addition of syringe standard prior to analysis, and large volume injection into the GC-MS. Parameter settings for the automated workflow are outlined in Table 1 with a visual overview provided in Figure 1. A list of accessories needed to configure the TriPlus RSH SMART autosampler is provided in the appendix (Table A2).&nbsp;After sample extraction was completed, a 30 μL aliquot of the pentane layer was directly injected into a programmable temperature vaporization (PTV) inlet. Injection and oven program conditions can be found described in Tables 1 and 2. Data acquisition was carried out using selected reaction monitoring (SRM) with a <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/485">Thermo Scientific™ TSQ™ 9610 triple quadrupole GC-MS</a> equipped with an Advanced Electron Ionization (AEI) source. Method parameters for data acquisition are summarized in Table 2 with optimized SRM transitions outlined in the appendix (Table A3).<h4>Conclusions&nbsp;</h4>Maintaining water quality is of both human and environmental health importance. However, due to the physical chemical properties of various organic substances, analytical methods require ultra-trace sensitivity and accuracy to quantify hazardous risks within both drinking and environmental surface waters. The results presented demonstrate that the developed automated workflow for online liquid-liquid extraction and analysis of water samples can meet these requirements:&nbsp;<ul><li>Ultra-trace sensitivity combining large volume injection with highly sensitive triple quadrupole GC-MS/MS, with over 70% of targeted analytes having limits of quantification below 2 ng/L&nbsp;</li><li>Compliant extraction recovery at part per trillion concentrations&nbsp;</li><li>Robust method precision over extended analysis time&nbsp;</li><li>Improved laboratory efficiency and productivity while reducing environmental impact with limited solvent consumption&nbsp;</li><li>Workflow customization capability through the Sampling Workflow Editor software</li></ul>

News from LabRulezGCMS Library - Week 45, 2025

Analysis of field samples in environmental laboratories can sometimes be complicated by how contaminated or “hot” the sample is. Many times “hot” samples have to be diluted in order to verify the level of contamination in the sample. The process of diluting samples is a time consuming process that can sometimes lead to human error when calculations are incorrect. A further problem is the loss of volatile organic compounds as the sample vial needs to be opened in order to perform the dilution.&nbsp;This poster will examine the benefits of automated dilutions. Since the syringe option of this system has the unique ability to dilute samples from two times to 400 times the original concentration, this study will examine the precision and accuracy for an array of dilutions in this comprehensive range. The dilution data will be compared to a manually prepared 50ppb calibration standard in order to determine the accuracy of the results. The precision will be established by examining four sequential dilutions and the percent relative standard deviation of the compounds’ respective area counts. Furthermore, in order to demonstrate the linearity of the dilutions, a calibration curve will be presented using the automated dilution option to prepare 200ppb standards for a calibration range of 0.5ppb (400x) to 200ppb (1x).<h4>Discussion&nbsp;</h4>Environmental laboratories often have to dilute field samples due to the analytes of interest having concentrations over the highest calibration level of the curve. In order to dilute these samples, the vial has to be opened and a portion of the sample has to be diluted manually and re-analyzed. Opening the vial can compromise the integrity of the sample as volatiles are lost when the seal of the vial is broken.&nbsp;EST Analytical has developed a syringe feature for the Centurion Autosampler that can dilute samples up to 400 times the original concentration. This feature is fully programmable and the sample vial does not have to be compromised in order to dilute the sample because the dilution process is automated. The sealed vial can be placed in the sample tray while the Centurion does all of the work.&nbsp;<h4>Experimental&nbsp;</h4>The <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/2159">Centurion WS autosampler</a> was configured with an <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/2160">Encon Evolution concentrator</a>. A Vocarb 3000 (K) trap was installed in the Evolution. Finally, the sampling system was connected to a GC/MS for sample analysis. The GC column employed for this study was an Rxi-624Sil MS 30m x 0.25mm x 1.4µm. Dilution Factors, Purge and Trap, and GC/MS parameters are listed below.<h5>Standard Concentration &amp; Dilution Factors</h5><ul><li>100ppb: 2x</li><li>250ppb: 5x</li><li>500ppb: 10x</li><li>2.5ppm: 50x</li><li>5ppm: 100x</li><li>10ppm: 200x</li><li>20ppm: 400x</li></ul><h5>Purge and Trap Parameters</h5><ul><li>Concentrator: EST Encon Evolution</li><li>Trap type: Vocarb 3000</li><li>Valve oven temperature: 150 °C</li><li>Transfer line temperature: 150 °C</li><li>Trap temperature: 35 °C</li><li>Moisture Reduction Trap (MoRT) temperature: 39 °C</li><li>Purge time: 11 min</li><li>Purge flow: 40 mL/min</li><li>Dry purge Temp.: Ambient</li><li>Dry Purge Flow: 40mL/min</li><li>Dry Purge Time: 1.0 min &nbsp;</li><li>Desorb pressure Control: ON</li><li>Desorb Pressure: 5psi</li><li>Desorb time: 0.5 min</li><li>Desorb preheat delay: 5 sec</li><li>Desorb temperature: 260 °C</li><li>MoRT bake temperature: 230 °C</li><li>Bake temperature: 265 °C</li><li>Sparge vessel bake temperature: 120 °C</li><li>Bake time: 8 min</li><li>Bake flow: 40 mL/min</li></ul><h5>GC/MS Parameters</h5><ul><li>System: <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=10&amp;search=7890%2F5975">Agilent 7890/5975</a></li><li>Inlet: Split mode, 200 °C, 40:1 split ratio, 12.153 psi head pressure</li><li>Column: Rxi-624Sil MS 30m x 0.25mm I.D. 1.4µm film thickness</li><li>Oven program: 45 °C (1 min) → ramp 18 °C/min → 220 °C, hold for 0.3 min</li><li>Column flow rate: 1 mL/min helium</li><li>Total flow: 44.0 mL/min</li><li>Source temperature: 230 °C</li><li>Quadrupole temperature: 150 °C</li><li>Transfer line temperature: 180 °C</li><li>Scan range: m/z 35–265, 3.12 scans/sec</li><li>Solvent delay: 0.7 min</li></ul>A 9 point calibration curve was manually prepared and run from 0.5 to 200ppb with standards ordered from Restek. After a linear calibration curve was established, a 50ppb calibration standard was run to establish instrument response for the compounds being analyzed. Next, a series of dilutions were run and compared with the initial 50ppb calibration standard. Each dilution factor was run four times with blanks in between. The final concentration of each dilution was 50ppb. The precision and accuracy of the dilutions are listed in Tables 4 and 5 and Figures 1 and 2 display the chromatograms of two of the dilutions.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/EST_Analytical_Figure_1_Overlay_of_50ppb_1_X_and_2500ppb_50x_Standards_29d90b4107.jpg" alt="EST Analytical: Figure 1 - Overlay of 50ppb (1X) and 2500ppb (50x) Standards" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_EST_Analytical_Figure_1_Overlay_of_50ppb_1_X_and_2500ppb_50x_Standards_29d90b4107.jpg 245w," sizes="100vw" width="1023" height="383"><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/EST_Analytical_Figure_2_Overlay_of_50ppb_1_X_and_10000ppb_200x_Standards_7f939589b9.jpg" alt="EST Analytical: Figure 2 - Overlay of 50ppb (1X) and 10000ppb (200x) Standards" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_EST_Analytical_Figure_2_Overlay_of_50ppb_1_X_and_10000ppb_200x_Standards_7f939589b9.jpg 245w," sizes="100vw" width="1073" height="383"><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/EST_Analytical_Table_4_Experimental_Results_2x_5x_10x_and_50x_dilutions_d81be1942f.jpg" alt="EST Analytical: Table 4 - Experimental Results (2x, 5x, 10x, and 50x dilutions)" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_EST_Analytical_Table_4_Experimental_Results_2x_5x_10x_and_50x_dilutions_d81be1942f.jpg 150w," sizes="100vw" width="1173" height="1220"><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/EST_Analytical_Table_5_Experimental_Results_100x_200x_and_400x_dilutions_f29762c72e.jpg" alt="EST Analytical: Table 5 - Experimental Results (100x, 200x and 400x dilutions)" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_EST_Analytical_Table_5_Experimental_Results_100x_200x_and_400x_dilutions_f29762c72e.jpg 124w," sizes="100vw" width="972" height="1226">Finally, a nine point calibration curve was run by setting up the system to do the dilutions. The curve was run using nine 40ml vials filled to volume with a 200ppb calibration standard and doing serial dilutions on the standards. For example, the 200ppb was diluted 400x for the 0.5ppb standard, 200x for the 1.0ppb standard, etc. See Table 6 for the curve dilutions and Table 7 for the curve linearity and compound responses.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/EST_Analytical_Table_6_Syringe_Curve_Dilutions_4237e1d568.jpg" alt="EST Analytical: Table 6 Syringe Curve Dilutions" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_EST_Analytical_Table_6_Syringe_Curve_Dilutions_4237e1d568.jpg 245w," sizes="100vw" width="785" height="381"><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/EST_Analytical_Table_7_Automated_Dilution_Curve_Results_356126f34f.jpg" alt="EST Analytical: Table 7 Automated Dilution Curve Results" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_EST_Analytical_Table_7_Automated_Dilution_Curve_Results_356126f34f.jpg 138w," sizes="100vw" width="927" height="1050"><h4>Conclusions&nbsp;</h4>The Centurion WS with the syringe option displayed remarkable precision and accuracy from as low as the 2x dilution to as high as 400x dilution. On the whole, the average precision of the instrument was less than 5%RSD while the overall accuracy was 90% to 110%. The system also is capable of curve automation with the average %RSD of below 10% for a 9 point curve from 0.5ppb to 200ppb. The automated dilution feature of the Centurion WS with the syringe option would enable laboratories to run samples more efficiently and the since the samples would not need to be compromised in order to perform dilutions, the accuracy of the experimental results would improve.

Automated Dilutions Using the Centurion Autosampler

Our Library never stops expanding. What are the most recent contributions to LabRulezGCMS Library in the week of 10th November 2025? Check out new documents from the field of the gas phase, especially GC and GC/MS techniques!<blockquote>👉 <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library">SEARCH THE LARGEST REPOSITORY OF DOCUMENTS ABOUT GCMS AND RELATED TECHNIQUES</a></blockquote><blockquote>👉 Need info about different analytical techniques? Peek into <a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/library">LabRulezLCMS</a> or <a target="_blank" rel="noopener noreferrer" href="https://icpms.labrulez.com/library">LabRulezICPMS</a> libraries.</blockquote>This week we bring you applicaton notes by Agilent Technologies, EST Analytical and Shimadzu!<h3>1. Agilent Technologies: Improved Thermal Stability Leads to Retention Time Stability and Data Accuracy for the Analysis of Pesticides</h3><ul><li>Application note</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/labrulez-bucket-strapi-h3hsga3/an_pesticide_gc_ms_5994_8447en_agilent_773f1f135b.pdf">Full PDF for download</a></li></ul>The analysis of trace-level pesticides is required by many governmental regulatory authorities at varying concentrations and can include hundreds of target analytes. As many of the matrices tested are complex and the analytes active, a robust and inert gas chromatography method is required.1 Heavy matrices can be difficult for analytical gas chromatography columns, and higher temperatures may be required to elute the matrix off of the column. To avoid damage from high temperatures and heavy matrix, a thermally stable and ultra inert analytical column phase is needed to successfully perform this analysis. The Agilent J&amp;W 5Q series of gas chromatography columns provide the most thermally stable column available and offer inertness for difficult analytes.2 The increased thermal stability not only dramatically reduces column bleed but also allows for less spectral interference at higher temperatures, leading to less need for background subtraction when searching analyte spectra against commercially available libraries.&nbsp;While column bleed is a normal phenomenon, the increase of the baseline due to column bleed is an indication of the column phase breaking down and leading to retention time shifts. Retention time shifting can be especially difficult with the analysis of pesticides, since sensitive detectors such as mass spectrometers and triple quadrupole systems collected in selected ion mode (SIM) or multiple reaction monitoring (MRM) mode are required to achieve lower limits of detection. In both SIM and MRM collection methods, time segment windows are stated for analytes of interest, and if a retention time shifts earlier, it can move out of the collection window and require time to update the analytical collection method. By using a GC column with increased thermal stability, such as the Agilent J&amp;W DB-5Q or the Agilent J&amp;W HP-5Q, the column will be more robust to thermal and matrix damage. These columns will also maintain consistent retention times over long periods of analytical stress.&nbsp;Retention time locking is a useful tool in the analysis of pesticides, as it can adjust column flow or pressure to normalize retention times, so that the retention times of the analytes are the same from system to system or column to column.3,4 When columns with identical selectivity are interchanged, after a single injection of a test mix, the analysis can be relocked and the column flow adjusted, based on the initial calibration, to be identical as in the original method. This eliminates the need to constantly update retention times in analytical methods for SIM or MRM windows or data processing methods when replacing analytical columns.&nbsp;When analyzing pesticides in heavy matrix, a guard column can serve two additional benefits. The guard column can help protect the analytical column from heavy matrix damage and can improve solvent and sample focusing. It is recommended to use nonpolar solvents when working with nonpolar column phases, such as the DB-5Q and HP-5Q columns. Recently it has become more common to prepare heavy matrices for pesticide analysis using QuEChERs-type preparations, with a final solvent of acetonitrile. Solvent-column phase polarity mismatch can lead to improper solvent focusing and wettability leading to improper peak shape, especially when working with columns that have low free silanol content on the deactivated surface of the fused silica. Use of a guard column can help to refocus the solvent and analytes to maintain proper peak shape.5&nbsp;The Agilent 7010D GC/TQ uses the new Agilent High Efficiency Source (HES) 2.0 equipped with a novel dipolar RF lens that redirects carrier gas and low mass ions by &gt;&nbsp;95%, helping to reduce noise and extend instrument robustness while maintaining sensitivity.6 When using DB-5Q and HP‑5Q columns in conjunction with the HES 2.0, it is possible to increase the overall robustness of the workflow for the analysis of pesticides over a wide dynamic range of analyte&nbsp;concentrations.&nbsp;<h4>Experimental&nbsp;</h4>An <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=10&amp;search=8890">Agilent 8890 GC</a> coupled with an <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=10&amp;search=5977B">Agilent 5977B GC/MSD</a> with an Inert Extractor Source was used for acquisition of data and <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=10&amp;search=MassHunter+10.0+Qualitative+Analysis">MassHunter 10.0 Qualitative Analysis software</a> was used for data analysis. NIST20 library was used to confirm peak identification. A retention gap of one meter was used as a guard column to help protect the analytical column from heavy matrix and to aid in solvent focusing.<h4>Results and discussion&nbsp;</h4>The analysis of pesticides requires retention time stability as well as consistency from analytical column to analytical column. To compare the analytical performance of an Agilent J&amp;W DB-5Q to an Agilent J&amp;W DB-5ms UI GC column for the analysis of pesticides, a standard was first analyzed on a DB-5ms UI and the retention time locked for chlorpyrifosmethyl. The DB-5ms UI column was then replaced with a DB-5Q, and once the column was conditioned, the representative pesticide mix was again analyzed and relocked to the appropriate retention time for chlorpyrifos-methyl and analyzed again. Figure 1 demonstrates the identical selectivity of the DB-5ms UI to the DB-5Q phases and the ability to relock an existing analytical method when upgrading columns and compatibility with existing retention time locking libraries.&nbsp;Additionally, when comparing the baseline of the DB-5Q to the DB-5ms UI column at the upper temperature limit of the chromatographic method, the increased thermal stability of the DB-5Q allows for a significant decrease in column bleed at upper temperature limits (Figure 1).<h4>Conclusion&nbsp;</h4>This application note demonstrated that the Agilent J&amp;W DB-5Q column has identical selectivity to the Agilent J&amp;W DB-5ms UI column, allowing for seamless adoption and use with existing retention time locking methods. The robust DB-5Q column phase maintained retention time stability even when analyzing heavy matrices and temperature cycling. The increased thermal stability not only decreased the baseline at higher temperatures but also allowed for less spectral interference and high library match factor scores. The analytical performance of the Agilent J&amp;W DB-5Q column coupled with the Agilent 7010D with the HES 2.0 ion source allows for optimal sensitivity and wide dynamic range of pesticide compounds.<h3>2. EST Analytical: Automated Sampling of Methanol Extractions</h3><ul><li>Application note</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/labrulez-bucket-strapi-h3hsga3/Purge_and_Trap_Automated_Sampling_of_Methanol_Extractions_f521577cc4.pdf">Full PDF for download</a></li></ul>Environmental labs are required to perform methanol extractions on highly contaminated solid waste samples. Additionally, these extractions are used for difficult matrices, for example oily waste samples, that are also soluble in methanol. Due to the variety of matrices that can be extracted with methanol there are assorted hurdles to cross in order to automate the sampling process. One of these obstacles is how the matrix can absorb the extraction solvent. For example, many soil samples require more methanol; due to the soil expanding with the solvent addition. Adding more methanol aids in rectifying this issue however, when automating sampling, the added methanol coupled with the soil expansion needs to be accommodated. For this reason, EST Analytical created software for the Centurion WS that allows the user to program the needle depth to different distances. In doing this, laboratories are able to sample soils at higher depths in order to adjust for sample absorption and at lower depths for samples that do not require the added solvent. In order to test volatile compounds in methanol extractions, a portion of the extract needs to be sampled from the vial, diluted, and purged on a purge and trap concentrator. This examination will look at the automated sampling of three different soil matrices.&nbsp;<h4>Experimental:&nbsp;</h4>The <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/2159">Centurion WS autosampler</a> with the syringe option and the <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/2160">Evolution purge and trap concentrator</a> were set up to run methanol extractions. Since this is a volatile analysis, a Vocarb 3000 (K) trap was used for the analytical trap. The sampling system was configured to an <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=1-10&amp;search=7890A">Agilent 7890A Gas Chromatograph (GC)</a> and an <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=1-10&amp;search=5975C">Agilent 5975C inert XL Mass Spectrometer (MS)</a>. The column selected for this analysis was a Restek Rxi®-624 Sil MS, with dimensions of 30m x 0.25mm I.D. x 1.4µm film thickness. Experimental parameters used for this analysis are listed in Tables 1 and 2.<h4>Conclusions:&nbsp;</h4>The system produced excellent results. The curve and the compound response factors met all of the method requirements. The overall precision was less than 5% RSD while the system showed an average recovery of 94%. When examining the expected analyte concentration to the extracted sand results, it was found that the average recovery was approximately 102%. Thus, the automated extraction performed extremely well. When comparing the three different matrices it was found that they all displayed similar recoveries, however the sand matrix did perform the best of the three as expected since sand tends not to absorb analytes as readily as other matrices. Finally, the ability to control the needle depth on extraction samples was a great benefit for the different matrices as the system exhibited no issues with needle clogging due to the higher needle depth when performing the potting soil extractions. As demonstrated from this study, the Centurion WS automated extraction capability would be an asset to any lab performing extractions.<h3>3. Shimadzu: Fatty Acid Analysis of Edible Oils by GC</h3>Comparing Helium and Hydrogen as Carrier GasesComparing Analysis by GC with a Simple Screening Analysis by LC-MS<ul><li>Application note</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/labrulez-bucket-strapi-h3hsga3/an_01_00852_en_e928ab40ea.pdf">Full PDF for download</a></li></ul>There are a variety of edible oils that are sold commercially for a range of uses. They are almost entirely composed of compounds called triacylglycerols (neutral lipids), which consist of three fatty acids bound to a glycerol molecule. Because fatty acids affect the functional characteristics of food, determining the fatty acid composition of food is an important area of analysis. In this Application News, the Brevis GC-2050 (GC-FID) is used to determine the fatty acid composition of commercially available edible oils, and the use of hydrogen as a carrier gas is examined and compared with helium. This Application News also analyzes the same edible oils analyzed by LC-MS in a previous Application News1) and comparesthe results.<h4>Equipment&nbsp;</h4>GC-FID analysis was performed using the <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=1&amp;search=Brevis+GC-2050">Brevis GC-2050</a> gas chromatograph (Fig.1) , which is designed to be highly compact, with an installation footprint 35 % smaller than the previous model. The Brevis GC-2050 is also equipped with a carrier gas saving mode that reduces carrier gas consumption. The carrier gas saving mode reduced the use of helium carrier gas by around 89 % and hydrogen carrier gas by around 79 % in the analyses described in this article. Hydrogen carrier gas also reduced analysis times by around 25 %.<h4>Results from Real-World Sample Analysis&nbsp;</h4>Edible oils were derivatized and analyzed using both helium and hydrogen carrier gases. Peaks that could not be identified with the calibration standard (37 FAME mixture) were analyzed by GC-MS to determine their carbon number and degree of unsaturation. (Labeled as isomer.) Fig. 4 shows the chromatograms (partial) obtained from analyzing linseed oil with helium and hydrogen carrier gases. Similar separation was achieved with both gases.<h4>Comparing GC-FID and FIA-MS&nbsp;</h4>Tables 5 and 6 compare the results of analyzing eight vegetable oils for fatty acids by FIA-MS (screening analysis) and GC-FID (a helium carrier). The results reveal characteristic features of the vegetable oils, such as the most abundant fatty acids, and that coconut oil contains fatty acids with relatively low carbon numbers. More information about the screening analysis performed with a single quadrupole mass spectrometer can be found in Shimadzu Application News 01-00674-EN. 1)<h4>Conclusion&nbsp;</h4>In this Application News, the Brevis GC-2050 was used to determine the fatty acid composition of edible oils. Fatty acid analysis is typically performed using helium as the carrier gas, but in this study, hydrogen was used. This reduced analysis times while producing results that compared favorably with helium. Given the current supply issues associated with helium, hydrogen should be considered as an alternative to helium.&nbsp;The results also show that fatty acid compositions determined by FIA-MS correlate well with results obtained by GC-FID. And because the sample pretreatment only requires sample dilution, analysis by FIA-MS is rapid, taking just 1 minute. Therefore, FIAMS seems particularly well-suited to the screening of large numbers of samples or when there is an urgent need to verify quality or safety

News from LabRulezGCMS Library - Week 46, 2025

Our Library never stops expanding. What are the most recent contributions to LabRulezGCMS Library in the week of 17th November 2025? Check out new documents from the field of the gas phase, especially GC and GC/MS techniques!<blockquote>👉 <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library">SEARCH THE LARGEST REPOSITORY OF DOCUMENTS ABOUT GCMS AND RELATED TECHNIQUES</a></blockquote><blockquote>👉 Need info about different analytical techniques? Peek into <a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/library">LabRulezLCMS</a> or <a target="_blank" rel="noopener noreferrer" href="https://icpms.labrulez.com/library">LabRulezICPMS</a> libraries.</blockquote>This week we bring you applicaton notes by Agilent Technologies, EST Analytical and Shimadzu!<h3>1. Agilent Technologies: Accurate Identification and Quantification of Pesticide Residues in Ghee</h3>Analysis by QuEChERS with GC/MS/MS using the Agilent 8890 GC and Agilent 7010 GC/TQ<ul><li>Application note</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/labrulez-bucket-strapi-h3hsga3/an_pesticide_ghee_gc_5994_8399en_agilent_1cbd787002.pdf">Full PDF for download</a></li></ul>India is one of the largest producers of milk, contributing about 23% of global milk production.1 The dairy processing sector includes a wide range of products, such as milk, butter, cheese, ghee, yogurt, flavored milk, lactose-free dairy products, and value-added products like ice creams and yogurts. Amongst these, ghee production is significant because of its popularity, low cost of production, and versatile use. According to the Food Safety and Standards Authority of India (FSSAI), ghee is mentioned as a "product obtained exclusively from milk, cream or butter by a process that almost completely removes water and non-fat solids; it has a specially developed flavor and physical structure".2 Milk‑producing animals can be exposed to pesticides through their diet, such as feed and fodder containing pesticide residues, or through the direct application of pesticides for controlling ectoparasites on their bodies, in animal sheds, and in milk processing areas. Due to their persistent and lipophilic nature, pesticides tend to accumulate in the fat-rich tissues of animals. The FSSAI has specified maximum residue levels (MRLs) for 55 pesticides, and a tolerance limit of 0.01&nbsp;mg/kg for the remaining pesticides for which an MRL has not been&nbsp;fixed.&nbsp;Ghee consists of 98.9% fat, irrespective of the animal source. Among the short- and medium-chain saturated fatty acids, all samples contain butyric (C4:0), caproic (C6:0), caprylic (C8:0), and capric acid (C10:0).3 Since its introduction, the <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=10&amp;search=QuEChERS">QuEChERS method</a> has been widely used for the analysis of pesticides in several matrices. Some modifications to the original QuEChERS method have been introduced to ensure efficient extraction of pH-dependent compounds, to minimize degradation of susceptible compounds (such as base- and acid-labile pesticides), and to expand the spectrum of matrices covered. Ghee matrix has a very high lipid load, making it a difficult commodity for analysis pesticide residues. The primary challenge lies in obtaining an extract that contains the target analytes while minimizing the amount of fat. Co-extracted lipids in the extracts can be removed, to a high degree, by a freezing-out step or a C18 cleanup.&nbsp;During sample extraction, the sample is often diluted. To obtain a quantification limit of 0.01 mg/kg, the instrument should be able to detect the residues at a lower concentration. This application note addresses these requirements by combining a sample preparation technique covering multiclass pesticides, target-specific multiple reaction monitoring (MRM) data acquisition, and efficient software to simplify quantitative analysis. The Agilent 7010 triple quadrupole GC/MS system enabled trace-level detection and confident quantitation of 150 pesticides in ghee.<h4>Experimental&nbsp;</h4><h5>Equipment&nbsp;</h5>An Agilent <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=10&amp;search=8890+GC">8890 GC</a> coupled to a <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=10&amp;search=7010+GC%2FTQ">7010 GC/TQ</a> system equipped with high efficiency source was used for the analysis. The GC system was equipped with a multimode inlet with air cooling and midcolumn backflush based on an Agilent purged Ultimate union controlled by a pneumatic switching device. The method parameters are displayed in Table 1.<h4>Conclusion</h4>The limits of quantitation (LOQs) for the target list of over 150 compounds ranged from 2.5 to 5 mg/kg for the ghee matrix. To minimize interferences from the ghee matrix, numerous multiple reaction monitoring (MRM) transitions were employed. This approach helped to accurately identify and quantify the target compounds despite the complex sample matrix. The samples were diluted five-fold to ensure that the analytes were within the required detection range of the instrument. This dilution also helped in reducing the matrix effects, leading to more reliable results. The average analyte recoveries were between 70 and 130%, indicating that the method has good accuracy and precision. This range of recoveries demonstrates the method’s robustness and suitability for routine analysis of these compounds.<h3>2. EST Analytical: Analysis of Coffee Flavors by Purge and Trap Sampling</h3><ul><li>Application note</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/labrulez-bucket-strapi-h3hsga3/Purge_and_Trap_Analysis_of_Coffee_Flavors_by_Purge_and_Trap_Sampling_ca25beef60.pdf">Full PDF for download</a></li></ul>Most of us who drink coffee know our preferences. We know which blend we like, what strength and definitely what we like in our coffee. However, most of us do not think about the flavors that go into our coffee that help us define our preferences. Coffee manufacturers, on the other hand are working diligently to create a new blend or a more satisfying flavor that would make us want to choose their coffee over another maker.&nbsp;This study will look at four different blends of coffee and some of the compounds that contribute to the flavor of the blend. Using purge and trap sampling, the flavor compounds were purged out of the coffee and trapped onto an adsorbent trap. The analytes were then transferred to a Gas Chromatograph/Mass Spectrometer (GC/MS) for analysis. The study focused on six flavor compounds. The spicy smoky aroma of 2-methylfuran, the spicy caramel, almond odor of 5-methylfurfural, the buttery scent provided by the addition of 2,3-butanedione and 2,3- pentanedione and the impact of the two and three methyl butanals giving the dark chocolate malty flavor to the coffee.<h4>Experimental:&nbsp;</h4>The EST Analytical <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/2160">Encon Evolution Purge and Trap Concentrator</a> and <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/2159">Centurion WS Autosampler </a>were interfaced to a GC/MS. The Centurion WS was run in the soil mode and the purge and trap concentrator was configured with a Vocarb 3000 (K) analytical trap. The column selected for this study was an Rtx-1 60m x 0.25mm x 1µm. Listed in Tables 1 and 2 are the experimental parameters used for this study.<h4>Conclusion:&nbsp;</h4>The lightest roast had the most buttery and dark chocolate/malty flavors while the darkest roast had more of the smoky flavor. Surprisingly, the darkest roast and the medium roast had similar proportions of the flavor compounds with the exception of the smoky flavor. While the light roast had large amounts of the flavors tested for, the chromatography of the light roast was much simpler than that of the darker roasts. Overall, the Encon Evolution Purge and Trap Concentrator in conjunction with the Centurion WS Autosampler proved to be an excellent system for sampling coffee. The results were reproducible and provided a lot of information on the flavors of the respective coffees.<h3>3. Shimadzu: Analysis of Ethanol in E10 Gasoline Using Polyarc Microreactor for GC</h3><ul><li>Application note</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/labrulez-bucket-strapi-h3hsga3/an_01_01033_en_d4ee66bd4f.pdf">Full PDF for download</a></li></ul>The flame ionization detector (FID) can detect almost all organic compounds, and the sensitivity of the obtained chromatograms displays a correlation with concentration and number of carbon atoms in the compound. However, as a weakness of FID, its sensitivity decreases when an organic compound contains oxygen atoms, asin the case of alcohols.&nbsp;The Polyarc microreactor improvessensitivity for alcohols and other compounds containing oxygen atoms (hereinafter, oxygenated compounds), allowing calibration using a single compound. Research and use of biofuels has accelerated in recent years, and more sensitive quantitative analysis of oxygenated compounds in multiple compoundsis now required.&nbsp;This Application News introduces an example of an analysis of a sample simulating E10 gasoline, in which 10 % ethanol by volume concentration was added to gasoline, demonstrating that enhanced sensitivity for oxygenated compounds can be achieved by adding Polyarc to the instrument configuration. The accuracy of the quantitative analysis was also verified using a general standard sample (alkane).<h4>Polyarc Microreactor</h4>Polyarc is a post-column type microreactor that is introduced between the column and the detector (FID). The organic compounds separated and eluted by the column are decomposed to methane by the Polyarc reactor in a two-stage oxidationreduction reaction (Fig. 1). Since the decomposed methane is detected by the FID, the uniform sensitivity for the carbon number can be obtained, regardless of the type of functional groups in a sample.<h4>Effective Carbon Number</h4>As mentioned above, the sensitivity of the FID detector varies depending on the types of functional groups in organic compounds. The detection sensitivity by the FID can be estimated based on the concept of the effective carbon number (ECN), which is an index showing how many carbon atoms in a compound function effectively. Depending on the type of functional groups contained in a compound, the carbon ratio in the molecule changes, and this causes changesin the sensitivity ofthe FID. For example, both ethane (C2H6) and ethanol (C2H5OH) contain the same number of carbon atoms of 2, but the sensitivity of the FID for ethanol is only 75 % of itssensitivity for ethane because the primary hydroxyl group (-OH) behaves as -0.5 carbon atoms in terms of its contribution to the ECN. This meansthe ECNof ethanol is 1.5. Table 1 shows several examples of other functional groups with ECNslowerthan the number of carbon atoms.<h4>Analysis Conditions</h4>In this Application News, sensitivity for ethanol when the Polyarc was added and when using only the FID was compared using an E10 sample, in which 10 v/v% ethanol was added to gasoline, simulating a biofuel which has attracted attention in recent years, and quantitativity for ethanol was confirmed. In the quantitative analysis, it was also carried out by the external standard method using a hydrocarbon (dodecane; C12) with a concentration of 1 w/v% as a standard sample. The analytical instrument was a <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=1&amp;search=GC-2030">GC-2030</a> (SPL/FID) model gas chromatograph with the Polyarc added (Fig. 2). Table 2 shows the analysis conditions.<h4>Conclusion</h4>E10 gasoline was analyzed using an FID detector and an added Polyarc microreactor, confirming that oxygenated compounds can be analyzed with high sensitivity. This study also confirmed that a uniform reaction of organic compounds can be obtained in the FID, and peak broadening can be suppressed by standardizing the response of sensitivity. Table 6 introduces several of the advantages that are possible by adding the Polyarc microreactor. The Polyarc converts all organic compounds to methane having the same number of carbon atoms (mol), enabling highsensitivity detection for compounds with low detection sensitivity by FID alone. In addition, since sensitivity is standardized, quantitation is possible using only one arbitrary calibration curve, regardless of the type of analysis compound. As a result, it is now possible to analyze compounds that were difficult to analyze by FID until now.

News from LabRulezGCMS Library - Week 47, 2025

<h4>Abstract&nbsp;</h4>The United States Environmental Protection Agency (USEPA) Method 8260 is used in order to ascertain volatile organic compounds in waters, soils and solid waste samples. Often times, soil and solid waste samples are so highly contaminated the sample needs to be dispersed in methanol. Sample collection for contaminated soils can be obtained in two ways. One, dispersing a bulk soil sample into a 40ml vial and adding methanol in the lab or two, sending preweighed vials with a septum sealed cap that already contains the pre-requisite methanol out in the field for soil sampling. No matter how the soil sample is dispersed in methanol, an aliquot of the methanol extract needs to be added to water and purged using USEPA Method 5030. This application will investigate automated sampling of methanol soil extractions.Introduction: Environmental labs are required to perform methanol extractions on highly contaminated solid waste samples. Additionally, these extractions are used for difficult matrices, for example oily waste samples, that are also soluble in methanol. Due to the variety of matrices that can be extracted with methanol there are assorted hurdles to cross in order to automate the sampling process. One of these obstacles is how the matrix can absorb the extraction solvent. For example, many soil samples require more methanol; due to the soil expanding with the solvent addition. Adding more methanol aids in rectifying this issue however, when automating sampling, the added methanol coupled with the soil expansion needs to be accommodated. For this reason, EST Analytical created software for the Centurion WS that allows the user to program the needle depth to different distances. In doing this, laboratories are able to sample soils at higher depths in order to adjust for sample absorption and at lower depths for samples that do not require the added solvent. In order to test volatile compounds in methanol extractions, a portion of the extract needs to be sampled from the vial, diluted, and purged on a purge and trap concentrator. This examination will look at the automated sampling of three different soil matrices.<h4>Experimental</h4>The <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/2159">Centurion WS autosampler</a> with the syringe option and the <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/2160">Evolution purge and trap concentrator</a> were set up to run methanol extractions. Since this is a volatile analysis, a Vocarb 3000 (K) trap was used for the analytical trap. The sampling system was configured to an <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=10&amp;search=7890A">Agilent 7890A Gas Chromatograph (GC) </a>and an <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=10&amp;search=5975C">Agilent 5975C inert XL Mass Spectrometer (MS)</a>. The column selected for this analysis was a Restek Rxi®-624 Sil MS, with dimensions of 30m x 0.25mm I.D. x 1.4µm film thickness. Experimental parameters used for this analysis are listed below.<h5>Purge and Trap Parameters</h5><ul><li>Concentrator: EST Encon Evolution</li><li>Trap type: Vocarb 3000</li><li>Valve oven temperature: 150 °C</li><li>Transfer line temperature: 150 °C</li><li>Trap temperature: 35 °C</li><li>Moisture Reduction Trap (MoRT) temperature: 39 °C</li><li>Purge time: 11 min</li><li>Purge flow: 40 mL/min</li><li>Dry purge Temp.: Ambient</li><li>Dry Purge Flow: 40mL/min</li><li>Dry Purge Time: 1.0 min &nbsp;</li><li>Desorb pressure Control: ON</li><li>Desorb Pressure: 6psi</li><li>Desorb time: 0.5 min</li><li>Desorb preheat delay: 15 sec</li><li>Desorb temperature: 260 °C</li><li>MoRT bake temperature: 210 °C</li><li>Bake temperature: 270 °C</li><li>Sparge vessel bake temperature: 120 °C</li><li>Bake time: 8 min</li><li>Bake flow: 85 mL/min</li></ul><h5>Purge and Trap Auto-Sampler: EST Centurion WS</h5><ul><li>Sample Type: Water</li><li>Water Volume: 5ml</li><li>Sample Prime Time: 5 sec</li><li>Loop Equilibration Time: 5 sec</li><li>Sample Transfer Time: 15 sec.</li><li>Syringe Rinse: On/6 ml</li><li>Number of Syringe Rinses: 2</li><li>Sample Loop Rinse: On/15 sec</li><li>Sample Sweep Time: 15 sec</li><li>Number of Sparge Rinses: On/2</li><li>Rinse Volume: 5 ml</li><li>Rinse Transfer Time: 15 sec</li><li>Rinse Drain Time: 25 sec</li><li>Internal Standard Vol.: 5 µl</li><li>Extraction: MeOH Prep A (Sand and Clay)</li><li>Extraction: MeOH Prep B (Potting Soil)&nbsp;</li></ul><h5>GC/MS Parameters</h5><ul><li>System: <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=10&amp;search=7890%2F5975">Agilent 7890/5975</a></li><li>Inlet: Split/splitless mode, 220 °C, 40:1 split ratio, 12.153 psi inlet head pressure</li><li>Column: Rxi-624Sil MS 30m x 0.25mm I.D. 1.4µm film thickness</li><li>Oven program: 45 °C (1 min) → ramp 15 °C/min → 220 °C, hold for 1.33 min, 14 min run time</li><li>Column flow rate: 1 mL/min helium</li><li>Total flow: 44.0 mL/min</li><li>Source temperature: 230 °C</li><li>Quadrupole temperature: 150 °C</li><li>Transfer line temperature: 180 °C</li><li>Scan range: m/z 35–300, 5.2 scans/sec</li><li>Solvent delay: 0.7 min</li></ul>The EPA method 8260 standards were acquired from Restek while the purge and trap grade methanol was procured from JTBaker. A nine point methanol curve was established from 0.5 to 200µg/L. Next Method Detection Limits (MDLs) were found running seven replicates of the low point on the curve. Precision and accuracy was determined by examining seven replicates of the 50µg/L standard. Table 3 displays the curve, MDL and precision and accuracy results. A set of three spiked sand matrix samples were used to establish the accuracy of the automated extraction at a 50µg/L concentration, see Table 4.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/EST_Analytical_Table_3_Curve_MDL_and_Precision_and_Accuracy_Results_38f2c858a9.jpg" alt="EST Analytical: Table 3 - Curve, MDL and Precision and Accuracy Results." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_EST_Analytical_Table_3_Curve_MDL_and_Precision_and_Accuracy_Results_38f2c858a9.jpg 159w," sizes="100vw" width="1102" height="1083"><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/EST_Analytical_Table_4_Results_of_Automated_Extraction_of_a_Sand_Matrix_3874d74191.jpg" alt="EST Analytical: Table 4 - Results of Automated Extraction of a Sand Matrix" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_EST_Analytical_Table_4_Results_of_Automated_Extraction_of_a_Sand_Matrix_3874d74191.jpg 91w," sizes="100vw" width="741" height="1267">Finally, sand, clay and soil matrices were extracted in order to compare the chromatography of the automated extractions using different matrices. The matrix comparison required 5 grams of soil and 15mls of methanol due to the potting soils’ absorption of the methanol. Thus, in order to make a direct comparison, all of the matrices were spiked with the same volume of standard and extracted with 15mls of methanol. Figure 1 displays a comparison of the three matrices and their respective interaction with the extraction solvent and Figure 2 shows the chromatograms of the three matrices.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/EST_Analytical_Figure_1_Image_of_5g_of_soil_matrices_in_15mls_of_Methanol_fc02a00c9d.jpg" alt="EST Analytical: Figure 1 - Image of 5g of soil matrices in 15mls of Methanol" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_EST_Analytical_Figure_1_Image_of_5g_of_soil_matrices_in_15mls_of_Methanol_fc02a00c9d.jpg 185w," sizes="100vw" width="565" height="477"><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/EST_Analytical_Figure_2_Chromatograms_of_Automated_Extraction_of_Sand_Clay_and_Soil_53e50f4fc4.jpg" alt="EST Analytical: Figure 2 - Chromatograms of Automated Extraction of Sand, Clay and Soil" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_EST_Analytical_Figure_2_Chromatograms_of_Automated_Extraction_of_Sand_Clay_and_Soil_53e50f4fc4.jpg 245w," sizes="100vw" width="1396" height="702"><h4>Conclusions</h4>The system produced excellent results. The curve and the compound response factors met all of the method requirements. The overall precision was less than 5% RSD while the system showed an average recovery of 94%. When examining the expected analyte concentration to the extracted sand results, it was found that the average recovery was approximately 102%. Thus, the automated extraction performed extremely well. When comparing the three different matrices it was found that they all displayed similar recoveries, however the sand matrix did perform the best of the three as expected since sand tends not to absorb analytes as readily as other matrices. Finally, the ability to control the needle depth on extraction samples was a great benefit for the different matrices as the system exhibited no issues with needle clogging due to the higher needle depth when performing the potting soil extractions. As demonstrated from this study, the Centurion WS automated extraction capability would be an asset to any lab performing extractions.

Automated Sampling of Methanol Extractions 

Our Library never stops expanding. What are the most recent contributions to LabRulezGCMS Library in the week of 24th November 2025? Check out new documents from the field of the gas phase, especially GC and GC/MS techniques!<blockquote>👉 <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library">SEARCH THE LARGEST REPOSITORY OF DOCUMENTS ABOUT GCMS AND RELATED TECHNIQUES</a></blockquote><blockquote>👉 Need info about different analytical techniques? Peek into <a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/library">LabRulezLCMS</a> or <a target="_blank" rel="noopener noreferrer" href="https://icpms.labrulez.com/library">LabRulezICPMS</a> libraries.</blockquote>This week we bring you brochure by Agilent Technologies, poster by LECO /MDCW, and application notes by Shimadzu and Thermo Fisher Scientific!<h3>1. Agilent Technologies: GC workflows for hydrogen vehicles and natural gas blending - Hydrogen Fuel Testing Solutions</h3><ul><li>Brochure</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/labrulez-bucket-strapi-h3hsga3/ac_hydrogen_fuel_purity_matters_compendium_5994_8643en_agilent_8da57fb7a2.pdf">Full PDF for download</a></li></ul>Agilent’s Hydrogen Fuel Testing Solutions compendium highlights the growing importance of reliable impurity analysis as hydrogen becomes a key clean-energy fuel. Because contaminants such as moisture, sulfur compounds, ammonia, oxygen, or organics can compromise fuel-cell performance and safety, the brochure emphasizes that hydrogen purity must be monitored throughout the entire supply chain—from production to storage, transport, and final distribution. Hydrogen blended into natural gas introduces additional challenges, since existing pipeline infrastructure was not originally designed for hydrogen, making rigorous analytical control essential for preventing corrosion, equipment malfunction, and safety issues.To address these challenges, Agilent presents a comprehensive suite of GC-based hydrogen testing workflows. The compendium showcases key analytical instruments—such as the <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=10&amp;search=8890">Agilent 8890 GC</a>, <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=10&amp;search=8355+SCD">8355 SCD</a>, 8255 NCD, <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=10&amp;search=5977C">5977C GC/MSD</a>, and portable <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=10&amp;search=990+Micro+GC">990 Micro GC</a>—each tailored for detecting critical impurities at trace levels in accordance with ISO 14687-2019, SAE J2719, and other global standards. Featured application notes demonstrate capabilities including ultratrace ammonia monitoring, analysis of sulfides and halides, sulfur speciation, and fast impurity screening for hydrogen and natural gas streams.Beyond instrumentation, the brochure outlines Agilent’s service ecosystem supporting method deployment, instrument verification, sustainability strategies, and lab operations management through CrossLab services and OpenLab software. These include preventive maintenance programs, financial solutions, certified pre-owned instruments, and consulting for analytical method development.Finally, the brochure connects hydrogen-fuel purity testing with broader sustainability goals. Agilent encourages laboratories to adopt circular-economy practices—reducing waste, extending instrument lifecycles, and improving energy efficiency—emphasizing that clean hydrogen starts with responsible, efficient, and reliable laboratory workflows.<h3>2. LECO / MDCW: BOOSTING NON-TARGETED ANALYSIS WITH COMPREHENSIVE TWO-DIMENSIONAL GAS CHROMATOGRAPHY AND HIGH-RESOLUTION MASS SPECTROMETRY</h3><ul><li>Poster</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/labrulez-bucket-strapi-h3hsga3/FL_18_Sebastiano_b4cf417f82.pdf">Full PDF for download</a></li></ul>The presentation by Sebastiano Panto (LECO EATC Berlin) focuses on demonstrating how comprehensive two-dimensional gas chromatography coupled with high-resolution time-of-flight mass spectrometry (<a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?instrumentationItems=2-13-3&amp;mainauthorItems=24">GC×GC-HR-TOFMS</a>) significantly enhances non-targeted and targeted screening workflows, particularly in environmental analysis. Using liver extracts from Glaucous gulls (Larus hyperboreus) from the Svalbard region as a case study, the work aims to reveal contamination patterns and improve compound identification confidence.Sample preparation included homogenization, lipid removal, and multi-step cleanup involving GPC/SEC chromatography and Florisil fractionation, yielding separate non-polar and polar fractions for analysis (page 4). Analytical separations were performed on an <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=10&amp;search=8890+GC">Agilent 8890 GC</a> equipped with a dual-column GC×GC setup (Rxi-5SilMS and Rxi-17SilMS), cryogenic modulation, and Helium carrier gas. Detection used the <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=24&amp;search=Pegasus+HRT%2B4D+HR-TOFMS">LECO Pegasus® HRT+4D HR-TOFMS</a> with multiple ionization modes—EI, PCI, and ECNI—enabling simultaneous acquisition of structural, isotopic, and exact-mass information (page 5).The results highlight the advantages of GC×GC-HR-TOFMS in non-target screening: improved separation patterns, higher library match scores, exact-mass confirmation, and enhanced structural elucidation. Electron ionization (EI) provided clean spectra with high match scores for classic pollutants (e.g., PCBs, DDE), while electron capture negative ionization (ECNI) greatly improved selectivity and sensitivity for halogenated contaminants such as toxaphenes and brominated flame retardants, enabling confident identification even when EI spectra were ambiguous (pages 6–13). The instrument’s high mass accuracy and isotopic fidelity are shown to be essential for distinguishing closely related halogenated compounds.The study concludes that combining GC×GC separation power with HR-TOFMS accurate-mass detection and complementary ionization modes offers a robust discovery platform for environmental exposomics. This analytical workflow supports more confident annotation of persistent organic pollutants (POPs) and emerging contaminants in complex biological matrices, ultimately helping assess ecological risks in sensitive Arctic ecosystems where these avian species reside (page 15).<h3>3. Shimadzu: High-Sensitivity Gas Analysis Using the GCMS-QP2050 and GI-30 Auto Gas Injector</h3><ul><li>Application note</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/labrulez-bucket-strapi-h3hsga3/an_01_00953_en_7e1a865aae.pdf">Full PDF for download</a></li></ul>Gas analysis is conducted across a wide range of fields, including resources, energy, and the environment. Typical targets include inorganic gases such as H2, CO, and CO2, and light hydrocarbon gases starting with CH4, with analyses primarily performed using GC. In Application News No. 01- 00858, examples of gas sample analysis using TCD and BID installed on the <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=1&amp;search=Brevis+GC-2050">Brevis GC-2050</a> were presented.&nbsp;However, qualitative analysis by GC requires standard substances, making the identification of unknown impurities in gas samples difficult. Furthermore, in inorganic gas analysis, complete chromatographic separation of peaks can be challenging, and when GC fails to fully separate them, both qualitative and quantitative analysis become difficult.&nbsp;In contrast, gas analysis using GC-MS enables qualitative identification of unknown components without standard substances through mass spectral library searches. Quantitation in GC-MS is performed using mass chromatograms, allowing accurate measurements even when peaks overlap.&nbsp;In this Application News, high-sensitivity analysis of inorganic gases and light hydrocarbon gases was performed using the compact yet high-performance <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=1&amp;search=GCMS-QP2050">GCMS-QP2050</a>. Gas samples were introduced using the <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=1&amp;search=GI-30">GI-30 Auto Gas Injector</a>, enabling automated, continuous analysis and delivering higher reproducibility than manual sample injection.<h4>Instrument Configuration and Analytical Conditions&nbsp;</h4>A 10 ppm standard mixed gas sample in a cylinder was analyzed using the GCMS-QP2050. Gas sample injection into the GC-MS was performed with the GI-30 Auto Gas Injector (P/N: S221- 89755-41). The instrument configuration is shown in Fig. 1. The analytical conditions used are summarized in Table 1. Under typical ionization settings (ionization voltage 70 V and emission current 60 µA), ionization of the helium carrier gas generates a significant signal at m/z 2, making detection of H2 (monitor ion: m/z 2) difficult. Therefore, for analysis in SIM mode, the ionization voltage was set to 20 V and the emission current to 20 µA to suppress He ionization.<h4>Automated Continuous Analysis Using the GI-30&nbsp;</h4>The GI-30 Auto Gas Injector is a sample pretreatment device that automatically introduces a fixed volume of gas into the GC. It is used by connecting either a gas cylinder or a sample bag. When the GI-30 is connected to a gas cylinder, automated, continuous analysis of gassamples becomes possible.&nbsp;The GI-30 is equipped with an optional valve purge mechanism. Purging the internal valve with gas reduces the ingress of ambient air. This is effective for analyzing components in ambient air, such as N2 and O2, as well as for measuring tracelevel components.&nbsp;Table 2 shows the peak-area repeatability (%RSD) obtained when a 10 ppm standard mixed gas was analyzed automatically and continuously in SIM mode. As an example, an overlay of the CH4 SIM chromatograms is shown in Fig. 3. Because the GI-30 meters a fixed volume of gas into the GC via a sample loop, excellent reproducibility was achieved for all compounds.<h4>Conclusion&nbsp;</h4>Using the GCMS-QP2050, high-sensitivity analysis of inorganic gases, such as H2, and light hydrocarbons was achieved. Gas sample injection was performed with the GI-30 Auto Gas Injector, enabling automated, continuous analysis and delivering higher reproducibility compared with manual sample injection. The compact, high-performance GCMS-QP2050, together with the GI-30, enables automation and high-precision gas analysis, and supports greater efficiency in GC-MS-based gas analysis.<h3>4. Thermo Fisher Scientific: Trace analysis of epichlorohydrin in drinking water using GC-MS coupled with purge and trap</h3><ul><li>Application note</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/labrulez-bucket-strapi-h3hsga3/an_003894_gc_single_quad_isq_7610_environmental_an003894_na_en_70123385ae.pdf">Full PDF for download</a></li></ul>Epichlorohydrin (ECH) is a versatile starting material in the production of drugs and polymers and is also used as an insect fumigant and solvent for organic synthesis reactions. ECH-based polymer pipes are commonly used in the production of drinking water due to their durability and resistance to corrosion. However, ECH is known for its high reactivity and toxicity, which poses significant health risks if it contaminates drinking water. Exposure to ECH can cause respiratory issues, skin irritation, and has been classified as a probable human carcinogen.Due to these risks, many countries have imposed strict limits on the amount of ECH allowed in drinking water. Recently, Europe set a minimum detection limit (MDL) of 30 parts per trillion (ppt) for ECH in drinking water.2 Whereas typically required detection limits for most compounds mandated for analysis in Europe can be achieved using methods based on static headspace, the stringent MDL required for ECH requires preconcentration, for example using purge and trap (P&amp;T) technology.3,4 This technology involves purging the water sample with an inert gas to release volatile organic compounds (VOCs), which are then trapped and concentrated for analysis, ensuring reliable detection at very low concentrations. In the United States, the analysis of VOCs in drinking water is mandated by the Environmental Protection Agency (EPA). The EPA requires the use of P&amp;T technology for drinking water analysis to ensure that even trace amounts of harmful compounds like ECH are detected and managed appropriately.&nbsp;The following evaluation describes the use of the ISQ 7610 Single Quadrupole MS system coupled with the Thermo Scientific™ TRACE™ 1610 GC with the Thermo Scientific™ HeSaver-H2 Safer™ split/splitless injector and Teledyne LABS Tekmar Lumin P&amp;T concentrator combined with the AQUATek LVA autosampler for the analysis of ECH in drinking water.<h4>Experimental</h4><h5>GC-MS parameters&nbsp;</h5>A <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/486">TRACE 1610 GC</a> was coupled to the <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/484">ISQ 7610 MS</a> equipped with the Thermo Scientific™ NeverVent ™ vacuum probe interlock (VPI) and an ExtractaBrite ion source. A <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/1773">Thermo Scientific™ TraceGOLD™ TG-VMS column</a>, 30 m × 0.25 mm, 1.4 µm film (P/N 26080-3320) was used for compound separation. The HeSaver-H2 Safer SSL injector was utilized to reduce the carrier gas consumption by decoupling the gas used for the chromatographic separation from the gas used to pressurize the inlet and maintain split and purge flows. The critical separations were maintained with a run time of under 15 minutes.For this analysis, the ISQ 7610 MS was operated in Selected Ion Monitoring (SIM) mode for increased selectivity, as required for this application. Extended method parameters for the ISQ 7610 MS are shown in Table 2.<h5>Instrument control and data processing&nbsp;</h5>Data was acquired, processed, and reported using the <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/76">Thermo Scientific™ Chromeleon™ Chromatography Data System (CDS)</a>. This software can control both the GC-MS system and the Tekmar Lumin P&amp;T with the AQUATek LVA. This allows a single software to be utilized for the full workflow, simplifying the instrument operation. This application note is available for download via the Thermo Scientific™ AppsLab Library, which contains all the parameters needed to acquire, process, and report the analytical data for analysis of ECH.5<h4>Conclusion&nbsp;</h4>This study demonstrates the capability of the Tekmar Lumin P&amp;T with the AQUATek LVA system connected to the ISQ 7610 Single Quadrupole GC-MS to detect and quantify low-level ECH in drinking water samples, in compliance with EPA requirements.&nbsp;<ul><li>Utilizing the Tekmar Lumin P&amp;T’s ability to purge with nitrogen, along with using the HeSaver-H₂Safer SSL injector, nearly four times less helium was consumed during the analysis without sacrificing system performance.&nbsp;</li><li>The linearity of the calibration curve from 30 ppt to 5,000 ppt passed method requirements.</li><li>The application proved robust during an extended study with 20 samples of a 1,000 ppt ECH standard injected over a series of 124 injections, obtaining 4.4% precision and 118% accuracy of the recovery.</li></ul>

News from LabRulezGCMS Library - Week 48, 2025

Our Library never stops expanding. What are the most recent contributions to LabRulezGCMS Library in the week of 1st December 2025? Check out new documents from the field of the gas phase, especially GC and GC/MS techniques!<blockquote>👉 <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library">SEARCH THE LARGEST REPOSITORY OF DOCUMENTS ABOUT GCMS AND RELATED TECHNIQUES</a></blockquote><blockquote>👉 Need info about different analytical techniques? Peek into <a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/library">LabRulezLCMS</a> or <a target="_blank" rel="noopener noreferrer" href="https://icpms.labrulez.com/library">LabRulezICPMS</a> libraries.</blockquote>This week we bring you application notes by Agilent Technologies, Shimadzu and Thermo Fisher Scientific and presentation by LECO /MDCW!<h3>1. Agilent Technologies: Analysis of 197 Pesticides in Durian by Agilent PAL 3 Autosampler and 7000E Triple Quadrupole GC/MSD</h3><ul><li>Application note</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/labrulez-bucket-strapi-h3hsga3/an_197_pesticides_durian_pal3_7000e_gc_msd_5994_8702en_agilent_e5a68eaf99.pdf">Full PDF for download</a></li></ul>Pesticide residue analysis in food products is critical to ensuring consumer safety and regulatory compliance. Durian (Durio zibethinus), known as the "king of fruits" and widely exported across Southeast Asia, China, and beyond, presents unique analytical challenges due to its sulfur-rich compounds, high fat content, and complex volatile matrix. Comprehensive pesticide analysis in such matrices demands highly sensitive, selective, and robust analytical solutions. The European Union Reference Laboratories (EURL) SANTE/11312/2021 guidelines set rigorous performance criteria for pesticide residue analysis, including strict requirements for method accuracy, precision, and sensitivity.1 Laboratories need to achieve recoveries between 70% to 120%, precision (RSD) below 20%, and quantification limits at or below regulatory maximum residue limits (MRLs), even in complex food matrices such as durian. This application note demonstrates a high-performance workflow for the analysis of 197 pesticides in durian using an Agilent PAL3 Autosampler combined with an Agilent 7000E Triple Quadrupole GC/MSD system. The PAL3 Autosampler provides high-throughput, precise sample handling, while the 7000E GC/MSD offers exceptional sensitivity and reproducibility for trace-level pesticide quantification. Optimized sample preparation and instrumental conditions ensure reliable performance, meeting and exceeding SANTE criteria for method validation.<h4>Experimental</h4><h5>PAL 3 RTC and 7000E GC/TQ parameters&nbsp;</h5>The analysis parameters are shown in Table 1. The target and ISTD compound MRM parameters are listed in Appendix&nbsp;1. Figure 1 shows a typical MRM chromatogram of targeted pesticides spiked in durian at a concentration of 100 ppb.<ul><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=10&amp;search=PAL+3">Agilent PAL 3 (Liquid Tool)</a></li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=10&amp;search=8890">Agilent 8890 GC</a></li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=10&amp;search=7000E">Agilent 7000E</a></li></ul><h4>Conclusion&nbsp;</h4>This study successfully demonstrated a robust and sensitive method for the quantitative analysis of 197&nbsp;pesticides in durian using an Agilent PAL3 Autosampler combined with an Agilent&nbsp;7000E Triple Quadrupole GC/MSD system. The optimized workflow, including sample extraction with an Agilent Bond Elut QuEChERS EN kit followed by cleanup with the Highly Pigmented dSPE kit, provided excellent recovery and precision. All target pesticides showed analysis accuracy between 80% and 120% and RSD values below 10% at a spiked level of 10 ppb. The results confirm the method's suitability for routine high-throughput pesticide quantification in complex matrices such as durian. The use of matrix-matched calibration and matrix‑optimized MRMs further ensured accurate and reproducible quantitation, reinforcing the method's applicability for regulatory and food safety testing.<h3>2. LECO / MDCW: Applying statistical data processing tools for GC×GC differentiation of alternative aviation fuels</h3><ul><li>Presentation</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/labrulez-bucket-strapi-h3hsga3/FL_18_Sebastiano_b4cf417f82.pdf">Full PDF for download</a></li></ul>The presentation introduces LECO’s long-standing role in separation science and its evolution from elemental analyzers to advanced mass spectrometry platforms. A key emphasis is placed on LECO’s innovations in time-of-flight mass spectrometry (TOFMS), including the Pegasus series and the new <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=24&amp;search=Pegasus+BTX">Pegasus BTX</a>, a benchtop TOFMS offering high sensitivity, rugged detector technology, fast spectral acquisition (1–500 spectra/s), and broad mass range (10–1500 m/z). This technological foundation supports comprehensive GC×GC-MS workflows essential for analyzing chemically complex matrices such as aviation fuels.A major focus of the talk is on software tools for non-targeted data processing. LECO’s software ecosystem—<a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=24&amp;search=ChromaTOF">ChromaTOF</a>, ChromaTOF Tile, and <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=24&amp;search=ChromaTOF+Sync">ChromaTOF Sync</a>—enables detailed deconvolution, quantitation, high-resolution spectral analysis, and especially statistical comparison of GC×GC datasets. ChromaTOF Tile uses a chromatographic “tiling” strategy to link datasets and detect differences between sample groups using three statistical metrics: Fisher Ratio, Coefficient of Variation (CoV), and Fold-Change. Each metric serves a different experimental purpose, from comparing traditional vs. synthetic jet fuels (Fisher Ratio) to exploring variability among multiple alternative fuel processes (CoV), or identifying additive components in two-sample comparisons (Fold-Change).The presentation demonstrates how raw GC×GC-MS data are curated into feature tables, statistically evaluated, and visualized in PCA plots, bar charts, and chromatographic overlays. For example, Fisher Ratio comparison highlights statistically significant chemical differences between conventional Jet A and synthetic fuels, while CoV analysis reveals clustering patterns among diverse synthetic fuel production pathways such as LT-FT SPK, HT-FT SPK, HEFA, SIP, ATJ, and CHJ. These workflows enable analysts to rapidly identify biomarkers or distinguishing compositional features within highly complex hydrocarbon matrices.Ultimately, the talk demonstrates that choosing the correct statistical processing method can dramatically simplify interpretation of complex GC×GC-MS datasets. LECO’s integrated instrumentation—particularly the Pegasus BTX TOFMS—and software platforms together provide a powerful toolkit for fuel characterization, quality evaluation, and differentiation of emerging alternative aviation fuels. By combining comprehensive chromatography with robust statistical approaches, researchers can gain deeper insights into chemical variability, production signatures, and additive packages in modern aviation fuel technologies.<h3>3. Shimadzu: Analysis of Formic Acid in Acetone Using GC/MS System</h3><ul><li>Application note</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/labrulez-bucket-strapi-h3hsga3/an_01_00957_en_e8b083b86e.pdf">Full PDF for download</a></li></ul>In research on artificial photosynthesis, the analysis of impurities in chemical products and raw materials has increased the demand for high-sensitivity analysis of formic acid. Previous examples of formic acid analysis using GC-BID and GC-FID (Jetanizer ) have been presented, but in this article high-sensitivity analysis of formic acid using the <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=1&amp;search=GCMS-QP2050">GCMS-QP2050</a> (see Fig. 1) isintroduced.<h4>Insert, Column Phosphoric Acid Treatment&nbsp;</h4>Formic acid is known to adsorb onto the injection port and column, making peak detection difficult. However, by performing phosphoric acid treatment on the glass insert and column before measurement, good peaks can be obtained. The procedure for phosphoric acid treatment of the glass insert is shown in Fig. 2, and the procedure for phosphoric acid treatment of the column isshown in Fig. 3.<h4>Conclusion&nbsp;</h4>By performing phosphoric acid treatment on the insert and column, it became possible to analyze formic acid in SIM mode down to 0.2 ppm. Furthermore, good results could be obtained for both linearity and repeatability. Additionally, by analyzing in Scan mode, identification of unknown peaks other than formic acid was also achieved.<h3>4. Thermo Fisher Scientific: Uninterrupted analysis of VOCs according to U.S. EPA Method 8260C using purge and trap and single quadrupole GC-MS technology</h3><ul><li>Application note</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/labrulez-bucket-strapi-h3hsga3/an_001018_gc_voc_analysis_gc_ms_epa_8260c_an001018_na_en_269857401c/an-001018-gc-voc-analysis-gc-ms-epa-8260c-an001018-na-en.pdf">Full PDF for download</a></li></ul>Volatile organic compounds, or VOCs, are human-made contaminants used and produced in the processing of, or as, paints, adhesives, petroleum products, pharmaceuticals, and refrigerants. Many of these compounds contaminate our environment and may cause negative health effects in humans and other living beings. Analytical laboratories must monitor a variety of sample types from the environment to ensure the public are not exposed to elevated levels of VOCs. The latest version of applicable method in the United States, U.S. EPA Method 8260C, is applicable when monitoring a variety of solid waste matrices for the presence of VOCs.To perform U.S. EPA Method 8260C, all method acceptance criteria must be achieved. These criteria include calculating the mean response factor and the relative standard deviation (RSD) of the response factors for target analytes. The RSD should be &lt;20%, with minimum response factors (RF) and MDLs for a wide range of target compounds. The analytical method must produce consistent results and be reproducible from day to day, with a continuing calibration verification (CCV) analyzed every 12 hours while samples are run. As the method covers varying matrices, it is important that the performance criteria are met in all samples of interest. The following evaluation describes the use of the ISQ 7610 GCMS coupled to the Atomx XYZ P&amp;T for U.S. EPA Method 8260C.<h4>Experimental</h4><h5>Instrument control and data processing&nbsp;</h5>Data were acquired, processed, and reported using <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/76">Chromeleon CDS software</a>, version 7.2. This software can control both the GC-MS system and the Tekmar Atomx XYZ P&amp;T. This enables a single software solution to support the full workflow, simplifying the instrument operation. The optimized method used within this application note is available for download via the Thermo Scientific™ AppsLab library. AppsLab contains all the parameters needed to acquire, process, and report the analytical data for U.S. EPA Method 8260C.2<h5>GC-MS parameters&nbsp;</h5>A <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/486">TRACE 1610 GC</a> was coupled to the <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/484">ISQ 7610 MS </a>equipped with the Thermo Scientific™ NeverVent™ vacuum probe interlock (VPI) and an ExtractaBrite™ ion source. Expanded method parameters for the GC-MS system are displayed in Table 3<h4>Conclusion&nbsp;</h4>The combined analytical solution with the TRACE 1610 GC coupled with the ISQ 7610 system and the Atomx XYZ P&amp;T system provides clear advantages for analytical testing laboratories that analyze environmental samples following the U.S. EPA Method 8260C requirements. The modularity of the TRACE 1610 GC as well as the ISQ 7610 VPI and ExtractaBrite ion source allows users to easily service the injection ports and to exchange ionization sources and analytical columns without venting the mass spectrometer, significantly reducing instrument downtime and minimizing sample analysis interruptions. The Atomx XYZ concentrator’s efficient trap cooling design reduces sample cycle time and allows for increased sample throughput. The moisture control system improves water vapor removal thereby reducing peak interference and increasing GC column life span.&nbsp;The experiments performed clearly demonstrate the suitability of this analytical configuration for the analysis of VOCs in various environmental samples in accordance with U.S. EPA Method 8260C with the following performance parameters as evidence:&nbsp;<ul><li>The ISQ 7610 VPI coupled with the Tekmar Atomx XYZ P&amp;T exceeds all the requirements outlined in U.S. EPA Method 8260C for analysis of VOCs in wastewater and solid waste.</li><li>Linearity was achieved with &lt;20%,&nbsp;relative standard deviation for both water and soil calibration curves for the majority of compounds.&nbsp;</li><li>The MDL and precision were assessed using n=7 replicates of a 0.2 ppb water standard and n=7 replicates of a 0.5 ppb soil standard. Calculated MDLs were &lt;0.2ppb and RSDs of calculated results were &lt;10% for most compounds in both the soil and water matrices.</li><li>System robustness was tested by continuously acquiring 240 injections of environmental samples over three days with no user intervention at all. The average %RSD of the calculated concentration was 8.30% with an average compound recovery of 90%.</li></ul>

News from LabRulezGCMS Library - Week 49, 2025

<h4>Abstract</h4>Desorb flow control was developed in order to help manage the moisture associated with the four minute desorb time required for USEPA method 524.2. An added benefit to this process is the reduction in helium consumption when using this technique. This application will explain the patented process of Desorb Flow Control (DFC) (United States Patent Office numbers: 8062905, 7951609, 7803635) for Helium conservation and moisture control.&nbsp;<h4>Introduction</h4>Helium has been an essential component in environmental testing for years. Since Helium is an inert gas with a similar diffusion speed as Hydrogen, it is ideal for using as a carrier gas in Gas Chromatography. In recent years, however, there has been an increasing shortage of Helium, leading laboratories to come up with different ways of conservation.&nbsp;Desorb Flow Control was developed to assist laboratories routinely running for USEPA Method 524.2. Method 524.2 requires a four minute desorb and laboratories are reporting issues with water when using the long desorb time. By using DFC, labs are now able to keep the required four minute desorb time and control the amount of water transferred to the GC by decreasing the flow through the trap during desorb while maintaining the desired split ratio at the GC inlet. Subsequently, DFC not only controls the amount of water transferred, but also decreases Helium consumption. See Figures 1 and 2.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/EST_Analytical_Figure_1_Traditional_GC_Flow_ebb2a6357c.jpg" alt="EST Analytical: Figure 1 - Traditional GC Flow" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_EST_Analytical_Figure_1_Traditional_GC_Flow_ebb2a6357c.jpg 245w," sizes="100vw" width="1106" height="553"><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/EST_Analytical_Figure_2_GC_Flow_with_Encon_Evolution_using_DFC_5af219d179.jpg" alt="EST Analytical: Figure 2 - GC Flow with Encon Evolution using DFC" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_EST_Analytical_Figure_2_GC_Flow_with_Encon_Evolution_using_DFC_5af219d179.jpg 245w," sizes="100vw" width="1389" height="684"><blockquote>(NOTE: The Encon Evolution provides the increased flow after the trap during desorb at a set time in the desorb process.)&nbsp;</blockquote>The advent of more efficient purge and trap systems and more sensitive GC/MS systems has aided in laboratories’ production. However, water control is still an issue. Labs may pass an initial calibration curve, but as water builds up in the system, internal standard response drops over time, causing the laboratory to fail continuing calibration checks. In order to combat water, many labs use a high split rate. As a consequence, Helium consumption is much higher and sensitivity is decreased. Using DFC, labs can still achieve the moisture control required thus creating a more stable system and lowering Helium consumption by as much as 80%, depending on the experimental split rate. See Table 1. *The table below assumes a throughput of 72 samples per day.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/EST_Analytical_Table_1_Daily_Helium_Consumption_ee240f3668.jpg" alt="EST Analytical: Table 1 - Daily Helium Consumption" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_EST_Analytical_Table_1_Daily_Helium_Consumption_ee240f3668.jpg 245w," sizes="100vw" width="1454" height="323"><h4>Experimental</h4>The sampling system used for this study was the <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/2160">EST Analytical Encon Evolution concentrator</a> and the <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/2159">Centurion WS autosampler</a>. The concentrator was affixed with a Vocarb 3000 trap and connected to an <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=10&amp;search=7890A">Agilent 7890A GC</a> and <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=10&amp;search=5975C">5975C inert XL MS</a>. The GC was configured with a Restek Rxi-624 Sil MS 30m x 0.25mm x 1.4µm column. Two different split ratios were used for comparison in this study, a 40:1 split rate was used for the baseline data and a 10:1 split rate was used for the DFC data. Experimental parameters used for this analysis are listed below.<h5>Purge and Trap Parameters</h5><ul><li>Concentrator: EST Encon Evolution</li><li>Trap type: Vocarb 3000</li><li>Valve oven temperature: 150 °C</li><li>Transfer line temperature: 150 °C</li><li>Trap temperature: 35 °C</li><li>Moisture Reduction Trap (MoRT) temperature: 39 °C</li><li>Purge time: 11 min</li><li>Purge flow: 40 mL/min</li><li>Dry purge Temp.: Ambient</li><li>Dry Purge Flow: 40mL/min</li><li>Dry Purge Time: 1.0 min &nbsp;</li><li>Desorb pressure Control: ON</li><li>Desorb Pressure: 13.5 psi</li><li>Desorb time: 4.0 min</li><li>Desorb preheat delay: 10 sec</li><li>Desorb temperature: 250 °C</li><li>MoRT bake temperature: 210 °C</li><li>Bake temperature: 260 °C</li><li>Sparge vessel bake temperature: 110 °C</li><li>Bake time: 8 min</li><li>Bake flow: 85 mL/min</li></ul><h5>Purge and Trap Auto-Sampler: EST Centurion WS</h5><ul><li>Sample Type: Water</li><li>Water Volume: 25ml</li><li>Internal Standard Vol.: 5 µl</li></ul><h5>GC/MS Parameters</h5><ul><li>System: <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=10&amp;search=7890%2F5975">Agilent 7890A/5975</a></li><li>Inlet: Split/splitless mode, 200 °C, 40:1 and 10:1 split ratio, 7.45 psi inlet head pressure</li><li>Column: Rxi-624Sil MS 30m x 0.25mm I.D. 1.4µm film thickness</li><li>Oven program: 40 °C (1.5 min) → ramp 8 °C/min → 100 °C, ramp 20 °C /min to 210 °C, hold for 1.25 min, 16.5 min run time</li><li>Column flow rate: 1 mL/min helium</li><li>Total flow: 13.8 and 43.8 mL/min</li><li>Source temperature: 230 °C</li><li>Quadrupole temperature: 150 °C</li><li>Transfer line temperature: 180 °C</li><li>Scan range: m/z 35–300, 3.12 scans/sec</li><li>Solvent delay: 1.0 min</li></ul>The USEPA Method 524.2 standards were acquired from AccuStandard. The linear ranges of the experiments were established by running eight point calibration curves from 0.5 to 100ppb. Table 4 displays curve linearity and compound response for the curves. Figure 3 displays chromatograms of the 20ppb calibration point with and without DFC. Finally, an experiment was run using Selective Ion Monitoring (SIM) of m/z 20 with and without DFC. This was done in order to show water control using D2O as the compound of interest so as not to SIM for water and overwhelm the MS. Figure 4 displays the results of this experiment.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/EST_Analytical_Table_4_Curve_Linearity_and_Compound_Response_Summary_7303558674.jpg" alt="EST Analytical: Table 4 - Curve Linearity and Compound Response Summary" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_EST_Analytical_Table_4_Curve_Linearity_and_Compound_Response_Summary_7303558674.jpg 107w," sizes="100vw" width="684" height="1003"><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/EST_Analytical_Figure_3_20ppb_Chromatograms_With_and_Without_DFC_bebdb4c00f.jpg" alt="EST Analytical: Figure 3 - 20ppb Chromatograms With and Without DFC" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_EST_Analytical_Figure_3_20ppb_Chromatograms_With_and_Without_DFC_bebdb4c00f.jpg 245w," sizes="100vw" width="1383" height="518"><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/EST_Analytical_Figure_4_Overlay_of_D2_O_mz_20_With_and_Without_DFC_701bb4011c.jpg" alt="EST Analytical: Figure 4 - Overlay of D2O mz 20 With and Without DFC" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_EST_Analytical_Figure_4_Overlay_of_D2_O_mz_20_With_and_Without_DFC_701bb4011c.jpg 143w," sizes="100vw" width="939" height="1026"><h4>Conclusions</h4>The results of this study show the patented Desorb Flow Control is an exceptional tool for conserving helium and creating a more stable system. The option of maintaining the desired split ratio at the GC inlet while decreasing the flow through the trap during desorb provides sensitivity while controlling the amount of moisture being sent onto the GC column. Furthermore, the split rate during the GC/MS run time is substantially lower than during the desorb time. Laboratories can have the advantage of running a higher split rate during the desorb process then maintaining a lower split during the rest of the GC/MS separation and analysis, thus providing laboratories with up to an 80% reduction in GC/MS helium use.

Benefits of Using Desorb Flow Control with the Encon Evolution

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