New strategies for non-targeted quantification in comprehensive two-dimensional gas chromatography: The potential of reconstructed TIC response factor surfaces

<p><strong>Our Library never stops expanding. What are the most recent contributions to LabRulezGCMS Library in the week of 18th August 2025? Check out new documents from the field of the gas phase, especially GC and GC/MS techniques!</strong></p><blockquote><p><span style="font-size:20px;">👉 </span><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library"><span style="font-size:20px;"><strong>SEARCH THE LARGEST REPOSITORY OF DOCUMENTS ABOUT GCMS AND RELATED TECHNIQUES</strong></span></a></p></blockquote><blockquote><p><strong>👉 Need info about different analytical techniques?</strong> Peek into <a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/library"><strong>LabRulezLCMS</strong></a> or <a target="_blank" rel="noopener noreferrer" href="https://icpms.labrulez.com/library"><strong>LabRulezICPMS</strong></a> libraries.</p></blockquote><p>This week we bring you poster by <strong>Agilent Technologies / ASMS </strong>and application note<strong> </strong>by<strong> Shimadzu!</strong></p><h3><strong>1. Agilent Technologies / ASMS: New Pollutant Screening of Environmental Samples Using High-Resolution GC/Q-TOF and Accurate Mass Spectral Library of Emerging Environmental Pollutants&nbsp;</strong></h3><ul><li>Poster</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/labrulez-bucket-strapi-h3hsga3/ps_7250_pdcl_library_pal3_suremass_asms_2025_thp_083_en_agilent_3f1ac53d50.pdf"><strong>Full PDF for download</strong></a></li></ul><p>This paper conducts qualitative and semi - quantitative analysis of complex GC/Q-TOF sample data by using high-resolution, accurate-mass gas chromatography/quadrupole time-of-flight mass spectrometry (GC/Q-TOF), an accurate mass spectral library of environmental pollutants specifically created for emerging pollutant screening, and analytical software with a screening process platform. Actual environmental water samples are used to verify the sensitivity, accuracy, and spiked recovery rate of the solution. All results confirm that this solution is simple, stable, and effective, providing technical support for emerging pollutant screening.</p><h4><strong>Experimental</strong></h4><h5><strong>Instrument Analysis&nbsp;</strong></h5><p>The samples were analyzed by <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=10&amp;search=8890+GC"><strong>Agilent 8890 GC</strong></a> and <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=10&amp;search=7250+GC%2FQ-TOF"><strong>7250 high resolution accurate mass GC/Q-TOF system</strong></a>, It was configurated with a mid-column backflush setup (Figure 1). A 55.5 - min retention time locked GC oven temperature program is utilized which is listed in Table 1. The key mass spectrometry parameters of the GC/Q-TOF are as follows: It operates in the Electron Ionization (EI) mode with an energy of 70 electron volts, conducts detection in the time-of-flight scan mode within a mass-to-charge ratio range of 50 - 1000. The spectral acquisition rate is 5 Hz, and both the interface temperature and the source temperature are set at 280 °C. Data analysis is performed with the assistance of MassHunter data analysis software. The high-resolution accurate mass spectral library employed in the screening process is independently created by the laboratory.</p><h5><strong>Data Analysis&nbsp;</strong></h5><ul><li>The data processing used Agilent <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=10&amp;search=Masshunter+software"><strong>Masshunter data analysis software</strong></a>, including Suremass.&nbsp;</li><li>The target screening of new pollutants was based on an independently created by the laboratory GC/Q-TOF PCDL library<sup>1</sup>.</li></ul><h4><strong>Conclusions&nbsp;</strong></h4><ul><li>Based on the currently collected list of new pollutants, a truly meaningful new pollutant PCDL high-resolution spectral library has been created.&nbsp;</li><li>This work demonstrated a total workflow for targeted screening and semi-quantification in real water sample.&nbsp;</li><li>The confidence in identification of new pollutants was enhanced by stable RT and excellent mass accuracy as a result of using an RTL backflush method and highresolution accurate mass measurement.</li></ul><h3><strong>2. Shimadzu: Analysis of SAF Using Comprehensive Two- Dimensional Gas Chromatography (GC× GC)&nbsp;</strong></h3><ul><li>Application note</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/labrulez-bucket-strapi-h3hsga3/an_01_00862_en_f1ee0a435f.pdf"><strong>Full PDF for download</strong></a></li></ul><h4><strong>User Benefits</strong></h4><ul><li>By comparing chromatograms obtained as two-dimensional images, it can be utilized for quality control Inspection of SAF.</li><li>Changing the column combination customizes separation characteristics to the sample composition.</li><li>Utilizing the FASST (Fast Automated Scan/SIM Type) allows for the simultaneous analysis of the composition of SAF and the quantitative analysis of antioxidants.</li></ul><p>SAF (Sustainable Aviation Fuel) produced from waste cooking oil, used paper, and sugarcane has gained attention in recent years from the perspective of achieving a carbon neutral society. The physical properties of SAF,such as combustibility, vary depending on its components. Therefore, component analysis of SAF is crucial; however, since SAF is a mixture of various hydrocarbons, complete separation of each component is extremely challenging. Comprehensive two-dimensional gas chromatography (GC×GC), which utilizes the separation characteristics of two different types of columns, is an effective method for analyzing SAF with such a complex composition. Additionally, the GCMS-QP2050 enables ultra-fast scanning (30,000 u/sec), which improves the separation of adjacent peaks and allows for high-precision qualitative analysis(Application News No.01-00788-EN).</p><p>In this application, two types of SAF (A and B) and one intermediate product from the SAF production process (C) were measured using a combination of GC×GC with a non-polar column as the first column and a medium-polarity column as the second column. The two-dimensional images allow for a visual representation of the composition distribution, making quality control Inspection. Moreover, high separation of paraffins and naphthenes using a combination of a medium-polar column as the first column and a non-polar column asthe second column, as well as the quantification of antioxidants in SAF, which are regulated by concentration in ASTM D2425 will be introduced.</p><h5><strong>System Configuration</strong></h5><ul><li><strong>GC Model</strong>: <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=1&amp;search=Nexis%E2%84%A2+GC-2030"><strong>Nexis GC-2030</strong></a> / <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=1&amp;search=AOC-30i"><strong>AOC-30i</strong></a></li><li><strong>MS Model</strong>: <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=1&amp;search=GCMS-QP2050"><strong>GCMS-QP2050</strong></a> (TMP exhaust: 255 L/sec)</li><li><strong>Injection Port</strong>: SPL</li><li><strong>Modulator: </strong>ZX1 thermal modulator (ZOEX corp.)</li><li><strong>Nitrogen generator: </strong>MT-24F (System Instruments Co., Ltd.)</li><li><strong>Software</strong>:<ul><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=1&amp;search=Labsolutions+GCMS"><strong>Labsolutions<sup>TM</sup> GCMS</strong></a></li><li>GC Image (GC Image, LLC)</li></ul></li><li><strong>Library: </strong>NIST Mass Spectral Library</li></ul><h4><strong>Conclusion</strong></h4><p>Three SAF samples were measured using a combination of lowpolar to medium polar columns and compared the twodimensional images. The two-dimensional images allow for intuitive comprehension of the distribution of each component, making it easy to identify differences in composition and conducting quality control Inspection. Additionally, in the measurement of SAF using a combination of medium-polar to non-polar columns, the separation of paraffins and naphthenes was improved. Furthermore, by utilizing the FASST, composition analysis of SAF and quantitative analysis of antioxidants were simultaneously performed, which are regulated by concentration in ASTM D2425.</p>

News from LabRulezGCMS Library - Week 34, 2025

<p><strong>Our Library never stops expanding. What are the most recent contributions to LabRulezGCMS Library in the week of 15th September 2025? Check out new documents from the field of the gas phase, especially GC and GC/MS techniques!</strong></p><blockquote><p><span style="font-size:20px;">👉 </span><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library"><span style="font-size:20px;"><strong>SEARCH THE LARGEST REPOSITORY OF DOCUMENTS ABOUT GCMS AND RELATED TECHNIQUES</strong></span></a></p></blockquote><blockquote><p><strong>👉 Need info about different analytical techniques?</strong> Peek into <a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/library"><strong>LabRulezLCMS</strong></a> or <a target="_blank" rel="noopener noreferrer" href="https://icpms.labrulez.com/library"><strong>LabRulezICPMS</strong></a> libraries.</p></blockquote><p>This week we bring you posters by <strong>Agilent Technologies / ASMS, Shimadzu / ASMS </strong>and application note by <strong>EST Analytical!</strong></p><h3><strong>1. Agilent Technologies / ASMS: Beyond Aligners: Unmasking Hidden Extractables and Leachables in Orthodontic Devices</strong></h3><ul><li>Poster</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/labrulez-bucket-strapi-h3hsga3/ps_7250_extractables_leachables_asms_2025_tp_318_en_ucsf_3e88cfbf5c.pdf"><strong>Full PDF for download</strong></a></li></ul><p>Increasingly popular in orthodontics, clear aligners promised to users’ improved comfort, compliance and flexibility. It also came with prolonged intraoral exposure. The literature on the potential for leaching components of the polymer used to manufacture the invisible aligners is sparse. Despite the benefits, user submitted cases in the FDA retrospective analysis report several adverse effect ranging from swelling, hives, itchiness and even difficulty breathing1 . Previous works examined the potential of leaching in retainers but used conditions far from the in-vivo setting2 . We used samples closest to user conditions and harnessed the power of Gas Chromatography High Resolution Mass Spectrometry (GC-HRMS) and the power of curated and annotated libraries to find candidate compounds that could be at the origin of the reported adverse effects. We also used multivariate statistics to establish relationships between the compounds and metadata.</p><h4><strong>Experimental</strong></h4><h5><strong>Sample Analysis&nbsp;</strong></h5><p>Samples were analyzed using the <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?manufacturerItems=1&amp;search=7250"><strong>Agilent 7250 accurate mass GC-qTOF</strong></a> equipped with the <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?manufacturerItems=1&amp;search=8890+GC"><strong>8890 GC</strong></a> and a DB-5MS UI column (30m x 0.25 x 0.25). The inlet temperature was 280°C and the transfer line temperature was 325°C. The oven program was as follows: 50°C for 1 min, ramp at 25°C to 170°C, hold for 1 min; then ramp at 15°C to 300°C, hold for 10 min; then ramp at 20 °C to 325°C and hold for 5 min. The solvent delay was 4 min. The data were acquired in electron ionization (EI) mode using mass range 45 to 1000 m/z. The source temperature was 230°C, and the emission current was 5 µA. A mix of alkanes was run along with the samples and blanks and an Extractables and Leachables (E&amp;L) standard mixture was run as a quality check.&nbsp;</p><h5><strong>Data Analysis&nbsp;</strong></h5><p>Retention indices were used in consolidating library matches in both the Agilent HRMS E&amp;L library and the NIST23 library. Data analysis was conducted on Unknown Analysis software from Agilent that performs compound annotation based on library matching and retention index. All compounds were individually reviewed based on ExactMass, retention index delta and library match factor (Figure 2). Canonical Correlation Analysis was performed using the FactoMineR package in R.</p><h4><strong>Conclusions</strong></h4><p>The aligners used in the current study were approved in the late 90s when E&amp;Ls methods were not as prominent or sensitive as they are today. This study stands out with:&nbsp;</p><ul><li>The first report of numerous E&amp;L compounds with known potential adverse effects in a population of clear aligner users&nbsp;</li><li>Providing an insight of the relationships between E&amp;Ls and user’s metadata such as age, DWT and TSS&nbsp;</li><li>Providing the necessary libraries to find parent compounds and their potential metabolites</li></ul><h3><strong>2. EST Analytical: Optimization of 1,4-Dioxane and Ethanol Detection Using USEPA Method 8260</strong></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_1_4_Dioxane_and_Ethanol_by_8260_App_Note_b669c79f53.pdf"><strong>Full PDF for download</strong></a></li></ul><p>During the manufacture of pharmaceuticals, 1, 4-Dioxane is used as a cleansing agent. It is also a byproduct of plastic manufacturing. The most likely exposure to 1, 4-Dioxane is at an industrial site. However, if any 1, 4-Dioxane is released into the environment during manufacturing there is a potential for it to migrate into ground water. The fact that 1, 4-Dioxane is so miscible in water makes degradation of the chemical challenging. Ethanol, on the other hand, has been a popular gasoline additive. Since it burns more quickly and completely than gasoline, emissions from car exhaust are decreased. The downside of this is underground storage tank leakage and fuel spills cause ground water and drinking water to be contaminated with both the fuel and the ethanol additive. Since ethanol is also very miscible in water, the detection of ethanol contamination in water can be difficult.&nbsp;</p><p>There have been several innovations that help overcome the obstacles of detecting 1, 4-Dioxane and Ethanol. The first one is the SIM mode of the mass spectrometer. This mode allows better detection of hard to extract compounds. Furthermore, mass spectrometers are now equipped to run SIM/Scan, this not only helps detect more difficult compounds, but also enables the detection of an extensive list of USEPA Method 8260 compounds without having to run the samples twice. Advancements in purge and trap sampling have also facilitated better detection of these compounds. Most effective in this has been the ability to heat the samples. However, there are drawbacks to better detection. The most problematic of these is the tendency of 1, 4-Dioxane and Ethanol to “stick” to the glass ware. This susceptibility has caused many headaches in environmental labs.&nbsp;</p><p>This application note will investigate seven variations of purge and trap sampling. The data will then be evaluated in order to recommend the optimum purge and trap sampling parameters for your lab.</p><h4><strong>Experimental</strong></h4><p>The sampling system used for this study was the <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/2160"><strong>EST Analytical Evolution concentrator</strong></a> affixed with a Vocarb 3000 trap. The <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/2159"><strong>Centurion WS autosampler</strong></a> equipped with the syringe option was employed as the autosampler. The separation and analysis were performed by an <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?manufacturerItems=1&amp;search=7890A"><strong>Agilent 7890A Gas Chromatograph (GC)</strong></a> and <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?manufacturerItems=1&amp;search=5975C"><strong>5975C inert XL Mass Spectrometer (MS)</strong></a>. The GC was configured with a <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?manufacturerItems=9&amp;search=Rxi-624+Sil+MS"><strong>Restek Rxi-624 Sil MS</strong></a> 30m x 0.25mm x 1.4µm column. The purge and trap parameters used for this study are listed in Tables 1 and 2 while Table 3 shows the GC/MS parameters.</p><h4><strong>Conclusions</strong></h4><p>All seven purge and trap parameter iterations passed the USEPA Method 8260 requirements for linearity and method detection limits. The problem with some of the experimental parameters was found in the carryover and precision and accuracy studies. The carryover using the traditional sparge vessel showed a large amount of carryover for the Ethanol and 1, 4-Dioxane. Since the carryover was so high, the precision and accuracy data suffered. The Fritless/Bulbless sparge vessel, on the other hand, displayed much lower carryover for the Ethanol and 1, 4-Dioxane especially when the patented sparge bake was not used. However, the 1, 2, 4-Trichlorobenzene, Naphthalene and 1, 2, 3-Trichlorobenzene carryover after the 50ppb standard was above the lower limit of the curve. Thus, the sparge bake would be recommended in order to limit the carryover of the heavier compounds. The optimum purge and trap parameters proved to be the patented water extraction technique. This technique provided linearity and method detection limits that met the USEPA Method 8260 requirements, while providing excellent precision and accuracy data. During water extraction, the sample is transferred to an empty 40ml vial and then purged in the soil station of the Centurion. The “fresh” vial provides a clean sparge vessel for every sample thus limiting carryover for both the Ethanol and 1, 4-Dioxane and for the heavy compounds. This lack of carryover aided in providing optimum precision and accuracy and carryover results and would be the recommended method for examining these troublesome compounds.</p><h3><strong>3. Shimadzu / ASMS: Quantitation of Acetaldehyde, Ethylene Oxide, 2-Chloroethanol, Ethylene Glycol, 1,4-Dioxane &amp; Diethylene Glycol in PEG 3350 by using dynamic headspace GC-MS/MS</strong></h3><ul><li>Poster</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/labrulez-bucket-strapi-h3hsga3/ASMS_2025_TP_301_ad1ab4ac3e.pdf"><strong>Full PDF for download</strong></a></li></ul><p>Polyethylene glycol 3350 (PEG 3350) is used to treat occasional constipation and it is in a class of medications called osmotic laxatives. PEG 3350 is an addition polymer of ethylene oxide and water with formula H(OCH2CH2)n OH, in which n represents the average number of oxyethylene groups. The average molecular weight of PEG 3350 is 3015–3685 g/mol (Da). Acetaldehyde, Ethylene Oxide (EtO), 2-Chloroethanol (2-CE), Ethylene Glycol (EG), 1,4- Dioxane and Diethylene Glycol (DEG) are the probable impurities of PEG 3350. All these above impurities are highly toxic &amp; hazardous substances.&nbsp;</p><p>As per the USP monograph, different chromatography techniques and sample preparation methods are used to quantify above mentioned impurities. This study reports a single sensitive and reliable analytical method for quantitation of all above impurities by using dynamic headspace (Trap) coupled with GC-MS/MS system. Limit of impurities and detail method of analysis are shown in table 1.</p><p>This study reports highly sensitive single method for the simultaneous quantification of multiple probable impurities of PEG 3350 by using dynamic headspace (Trap) coupled with triple quadrupole gas chromatography (GC-MS/MS) system.&nbsp;</p><h4><strong>Materials and methods&nbsp;</strong></h4><p>For this study, individual impurity reference standards were procured from Sigma Aldrich, whereas PEG 3350 powder sample was procured from local medical store. 10% of PEG 3350 powder sample solution (as such sample solution) and respective levels of matrixmatched calibration standard solutions were prepared in acetonitrile. Standard addition method was used to quantify impurities in the PEG 3350 sample. This method was part validated with respect to (w.r.t) precision, linearity/accuracy and sample analysis. <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?manufacturerItems=3&amp;search=GCMS-TQ8050+NX"><strong>GCMS-TQ8050 NX</strong></a> equipped with headspace sampler <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?manufacturerItems=3&amp;search=HS-20+NX"><strong>HS-20 NX </strong></a>(Trap) (Figure 1), manufactured by Shimadzu Corporation Japan, was used to quantify impurities in the PEG 3350 sample</p><h4><strong>Conclusion</strong></h4><ul><li>Trace level quantification of Acetaldehyde, EtO, 2-CE, 1,4-Dioxane, EG and DEG in PEG 3350 sample was successfully performed by using Shimadzu GCMS-TQ8050 NX with HS-20 NX (Trap) dynamic headspace sampler.</li><li>Dynamic headspace mode outperforms the current regulatory limits, delivering multifold times more sensitivity compared to other injection techniques.</li><li>Shimadzu GCMS-TQ8050 NX features a new highly efficient detector and superior noise reduction technology that enhance sensitivity and enables quantitation of impurities even at trace levels.</li></ul>

News from LabRulezGCMS Library - Week 38, 2025

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