In this technical tip from Phenomenex, the topic of gas chromatography (GC) column trimming is addressed from a troubleshooting perspective. The key question explored is whether trimming a GC column is necessary and how it impacts chromatographic performance.<h3>Why Trim a GC Column?</h3>Column trimming is primarily used to restore chromatographic performance by removing damaged or contaminated sections, typically located at the column inlet.<h5>1. Baseline Bleed, Noise, Ghost Peaks, Poor Peak Shape</h5><ul><li>Cause: Column contamination</li><li>Removing the contaminated stationary phase at the column entrance helps restore performance.</li></ul><h5>2. Elevated Baseline (Especially at High Temperature)</h5><ul><li>Cause: Column bleed</li><li>Degradation of the stationary phase due to oxygen exposure or thermal damage leads to increased baseline.</li></ul><h5>3. Ghost Peaks (Peaks Without Injection)</h5><ul><li>Cause: Residual sample or contamination</li><li>Compounds trapped at the beginning of the column can appear as peaks even when no sample is injected.</li></ul><h5>4. Peak Tailing (Asymmetrical Peaks)</h5><ul><li>Cause: Damaged or contaminated column sections</li><li>These issues result in adsorption effects or poor flow dynamics.</li></ul><h5>5. Retention Time Shifts</h5><ul><li>Cause: Contamination or damage near the inlet</li><li>Although trimming slightly changes retention time, it can correct shifts caused by inlet-side issues.</li></ul><h5>6. Baseline Noise and Spikes</h5><ul><li>Cause: Particulate matter or degraded stationary phase</li><li>These can lead to detector instability and random signal fluctuations.</li></ul><h5>7. Baseline Drift or Wander</h5><ul><li>Cause: Contamination or oxidized column sections</li><li>Removing these regions stabilizes the baseline.</li></ul><h5>8. Loss of Resolution or Sensitivity</h5><ul><li>Cause: General column degradation</li><li>Trimming removes the most exposed and damaged portions, effectively rejuvenating column performance.</li></ul><h3>How to Trim a GC Column</h3>A capillary GC column consists of:<ul><li>Polyimide outer coating (protective layer)</li><li>Fused silica tubing (fragile but flexible core)</li></ul><h3>Step-by-Step Procedure</h3><h5>1. Scoring the Column</h5><ul><li>Use a ceramic wafer</li><li>Hold it at an inclined angle</li><li>Score the polyimide coating perpendicular to the column</li></ul><h5>2. Breaking the Column</h5><ul><li>Perform a quick, decisive flick</li><li>This ensures a clean, square cut</li></ul><h5>3. Inspecting the Cut</h5>After trimming, visually inspect the column end.<h3>Examples of Column Cuts</h3><h4>Good Cut</h4><ul><li>Clean, square end</li><li>Ensures proper sealing and connection</li></ul><h5>Bad Cuts</h5><ul><li>Slight Irregularity<ul><li>Small imperfection at the edge</li><li>Can cause leaks and active sites</li></ul></li><li>Poor / Rough Cuts<ul><li>Uneven or jagged edges</li><li>Lead to:<ul><li>Poor connections</li><li>Active sites</li><li>Peak tailing</li></ul></li></ul></li></ul><h2>Conclusion</h2>Trimming a GC column is a simple yet effective troubleshooting step. By removing contaminated or damaged sections—especially near the inlet—it can resolve a wide range of chromatographic issues, including baseline instability, ghost peaks, and loss of performance.Proper cutting technique is essential to avoid introducing new problems such as leaks or active sites.

Trimming a GC Column: Purpose, Symptoms, and Proper Technique

Our Library never stops expanding. What are the most recent contributions to LabRulezGCMS Library in the week of 30th March 2026? 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, Thermo Fisher Scientific, brochure by Shimadzu and presentation by MDCW / LECO!<h3>1. Agilent Technologies: Extraction and Analysis of Pesticides from Water by Solid Phase Extraction and GC/MS</h3><ul><li>Application note</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/labrulez-bucket-strapi-h3hsga3/an_extraction_analysis_pesticides_water_gcms_5994_8996en_agilent_28fc35d0e7.pdf">Full PDF for download</a></li></ul>Drinking water is defined as water intended for human consumption obtained from different sources. Several guidelines/regulations exist for ensuring that undesirable substances such as pesticides are not present in excessive amounts that may be harmful to human health. These regulations ensure that water intended for human consumption can be consumed safely. In India, the Bureau of Indian Standards (BIS) has set regulatory limits for residual pesticides in drinking water (IS 10500)1 , packaged drinking water (IS 14543)2 , and natural mineral water (IS 13428).3 A total of 26 pesticides are regulated by BIS standards, of which four compounds (monocrotophos, phorate, 2,4-D, and isoproturon) are more suitable for analysis by liquid chromatography.&nbsp;EPA Method 525.2 is a general-purpose method for determination of organic compounds in finished drinking water or water from any source or treatment stage.4 This method is applicable to a range of organic compounds that are partitioned from the water sample onto a C18 organic phase packed in a disk or cartridge. The organic compounds are then eluted using a suitable eluent, concentrated, and analyzed by GC/MS.&nbsp;This application note describes the use of EPA Method 525.2 for extraction of pesticide residues at trace levels in water using solid-phase extraction (Agilent Bond Elut C18: Straight barrel cartridges, p/n 12102118) and analysis using Agilent 8890-5977 GC/MS.&nbsp;Excellent linearity with R2 &gt; 0.995 was obtained for all pesticides considered for the study. Recoveries were obtained in the range of 80–120% with associated RSDs &lt; 15% at 0.005–0.080 ng/mL level of fortification.<h4>Experimental</h4><h5>Instrument parameters</h5><ul><li>GC: <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?manufacturerItems=1&amp;search=8890">Agilent 8890</a></li><li>Column: Agilent <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?manufacturerItems=1&amp;search=J%26W+HP-5ms">J&amp;W HP-5ms</a> UI 30 m × 0.25 mm, 0.25 μm&nbsp;</li><li>Carrier Gas: Helium, constant flow, 1.2 mL/min&nbsp;</li><li>Inlet: Agilent Multimode Inlet (MMI)</li><li>MS: <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?manufacturerItems=1&amp;search=5977">5977 GC/MS</a></li></ul><h4>Conclusion&nbsp;</h4>A simple, easy, and efficient method based on EPA 525.2 was implemented for the determination of 22 pesticides in water. The method demonstrated good sensitivity, precision, and accuracy, and allows for rapid analysis. The results demonstrate that pesticide residues can be detected below the current maximum residue levels (MRL) required by the BIS specifications. Acceptable recoveries and precision were obtained at concentrations as low as 5 ng/L for all pesticides. The method is ideally suited for use in a regulatory laboratory for the determination of pesticides in surface, drinking, and packaged drinking water.<h3>2. MDCW / LECO: Exploring PFAS in Consumer Goods Using GCxGC and High-Resolution Mass Spectrometry</h3><ul><li>Presentation</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/labrulez-bucket-strapi-h3hsga3/O_3_Alonso_6f61e3ea43.pdf">Full PDF for download</a></li></ul>Per- and polyfluoroalkyl substances (PFAS) are widely used in consumer and industrial products due to their unique physicochemical properties, but their persistence and potential health risks have made their detection increasingly important. This study focuses on developing an untargeted analytical approach for screening PFAS and related compounds in consumer goods using advanced chromatographic and mass spectrometric techniques.The analytical workflow combines gas chromatography with time-of-flight mass spectrometry (GC-TOFMS) and comprehensive two-dimensional gas chromatography coupled with high-resolution TOFMS (GC×GC-HRTOFMS), using systems such as the <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/1097">LECO Pegasus® BTX </a>and <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/38">Pegasus® HRT+</a> platforms. Sample introduction is performed via thermal desorption or pyrolysis, enabling analysis of both volatile and complex matrices. High-resolution MS provides accurate mass measurements and elemental composition, which are essential for identifying unknown compounds and reducing matrix interferences.In the first case study, anti-fog solutions were analyzed and found to contain a wide range of compounds, including fluorotelomer alcohols and related PFAS species. While GC-TOFMS enabled initial screening, high-resolution TOFMS was necessary to characterize unknown compounds through accurate mass determination and complementary ionization techniques (EI and PCI). This approach allowed tentative structural assignment using external databases, demonstrating the importance of HRMS in identifying compounds not present in standard libraries.The second case study focused on chewing gum, a highly complex matrix with diverse chemical constituents and trace-level analytes. The use of GC×GC-HRTOFMS significantly improved chromatographic separation and spectral clarity, enabling detailed profiling of volatile and semi-volatile compounds. A dedicated PFAS screening workflow based on mass defect analysis and spectral filtering was applied, leveraging the characteristic CF₂ patterns of PFAS molecules to simplify data interpretation.Despite the complexity of the sample, no PFAS were detected in the chewing gum, its packaging, or the box. Overall, the study demonstrates that combining GC×GC separation, high-resolution mass spectrometry, and advanced data processing tools provides a powerful and reliable strategy for untargeted PFAS screening in complex consumer products, particularly when unknown or emerging contaminants are of concern.<h3>3. Shimadzu: Gas Chromatograph Nexis GC-2060</h3><ul><li>Brochure</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/labrulez-bucket-strapi-h3hsga3/c184_e056_06c3456516.pdf">Full PDF for download</a></li></ul>The Shimadzu <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?manufacturerItems=3&amp;search=Nexis+GC-2060">Nexis GC-2060</a> represents a new generation of gas chromatographs, built on over 70 years of GC development and designed to serve as a flexible and future-proof analytical platform. It integrates the concept of Analytical Intelligence, which enables automated system monitoring, troubleshooting, and optimization, helping both experienced and less experienced users achieve reliable and consistent results. The system is highly configurable, supporting up to two injectors, three injection units, and four detectors simultaneously, allowing a single instrument to cover multiple analytical applications.A key advantage of the Nexis GC-2060 is its versatility in sample introduction and detection. The Multi-Mode Injection Unit (MMI) supports a wide range of injection techniques, including split/splitless, PTV, direct injection, large-volume injection (LVI), and thermal desorption, significantly reducing the need for complex sample preparation. The system is also equipped with next-generation detectors such as FID and TCD, offering high sensitivity, stability, and linearity, with additional detector options (ECD, FPD, FTD, BID) enabling broad application coverage.The instrument is designed to maximize laboratory efficiency and minimize downtime. Features such as tool-free column installation (ClickTek), automated startup/shutdown, Easy sTop maintenance mode, and Clean Pilot for automated column conditioning simplify routine operation and reduce manual intervention. In addition, Eco Idling technology automatically optimizes gas and power consumption during standby, significantly lowering operational costs while maintaining readiness for analysis.From an analytical performance perspective, the Nexis GC-2060 delivers excellent reproducibility and sensitivity, supported by advanced autosamplers (e.g., AOC-30) and compatibility with third-party systems. The platform supports hydrogen carrier gas for faster analysis and includes smart gas management features such as automatic gas switching. Its modular design allows seamless integration with various sample preparation systems, autosamplers, and detectors, ensuring adaptability to evolving laboratory needs.Overall, the Nexis GC-2060 combines high performance, operational efficiency, and flexibility in a single platform, making it suitable for a wide range of applications, including pharmaceutical analysis, environmental testing, food analysis, and energy-related measurements. Its scalability and continuous software updates ensure long-term usability and alignment with future analytical requirements.<h3>4. Thermo Fisher Scientific: Accurate multi-component blast furnace gas analysis maximizes iron production and minimizes coke consumption</h3><ul><li>Application note</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/labrulez-bucket-strapi-h3hsga3/epm_AN_Iron_Production_Prima_PRO_bd5de98b44.pdf">Full PDF for download</a></li></ul>Over a billion tonnes of iron a year are produced in blast furnaces, representing around 94% of global iron production¹. The blast furnace consists of a large steel stack, lined with refractory brick. Iron ore, coke and limestone are dropped into the top of the furnace and preheated air blown into the bottom through nozzles called ‘Tuyeres’. Iron oxides are reduced in the melting zone, or ‘Bosh’, forming liquid iron (called ‘hot metal’) and liquid slag. These liquid products are drained from the furnace at regular intervals, and the blast furnace will run continuously for several years, until the refractory lining needs replacing.Analysis of carbon monoxide (CO) and carbon dioxide (CO₂) give vital information on the efficiency of the reduction processes. Historically, two non-dispersive infrared (NDIR) analyzers were used, one to measure CO, the other CO₂. Additional discrete analyzers were required to monitor oxygen and hydrogen – typically paramagnetic O₂ analyzers and thermal conductivity analyzers for H₂.&nbsp;Thermo Scientific™ process mass spectrometers have been widely used for many years for key gas analysis applications in iron and steel plants, including blast furnace, basic oxygen steelmaking, coke oven gas analysis, secondary steel process control, fuel gas analysis and direct reduction iron processes²<h4>Process control requirements&nbsp;</h4>The advantages of process MS over conventional analysis techniques have been proven over many years in the iron and steel industry. The ability to measure a wide range of components on a single analyzer, coupled with advanced calibration, data transmission, and self-diagnostic software, makes the modern mass spectrometer ideal for integration into the modern plant. On blast furnaces, superior gas analysis is being used to calculate gas efficiency, mass and heat balances, and heat profiles through probe analysis, as well as being an essential tool in the early detection of cooling water leaks and sample system failures.&nbsp;Figure 2 shows 64 hours of data from a <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/2305">Thermo Scientific™ Prima™ PRO Process MS</a> monitoring the six gases in a blast furnace top gas every 10 seconds. The pulse every 12 hours is generated by an automatic nitrogen blowback from the sample conditioning system, to keep the sample probe clear of particulates.<h4>Hydrogen analysis&nbsp;</h4>An increase in the hydrogen level in the furnace can indicate a leak from the furnace cooling system, as water dissociates into hydrogen and oxygen in the furnace. This has implications both for plant efficiency and plant safety. Water leaks will lower the furnace temperature, causing heat loss and a consequent increase in fuel consumption. In extreme cases, damage to plant and personnel can be caused by ignition of these hazardous mixtures of explosive gases.&nbsp;Figure 4 shows a plot of top gas hydrogen concentration measured by Thermo Scientific process MS over a 24-hour period, with the departure of the measured H2 value from that predicted by the mass balance model indicating a water leak. This leak was caused by the failure of a cooling member, and the furnace was taken off blast for repair. The mass spectrometer’s ability to provide fast, accurate hydrogen analysis removes the need for an additional discrete analyzer.&nbsp;Gas composition measurement is particularly important during the end-of-campaign blowdown that takes place prior to rebuilds and relines, because explosive gas mixtures can be generated.&nbsp;<h4>Probe analysis&nbsp;</h4>The fast analysis provided by MS offers another significant advantage over discrete analyzers—a number of process streams can be analyzed using a single instrument. This is achieved using a fully automated multi-inlet system, designed to switch between sample streams at high speeds with minimal sample flushing times. For example, as well as furnace top gas, the MS can also analyze gases from probes placed above and below the burden (the furnace charge of iron ore, coke and limestone). These are known as above-burden and sub-burden probes and provide valuable information on fuel efficiency, iron conversion and furnace charging. Figure 5 shows a schematic of these two probes; they can be moved across the furnace to build a cross-sectional profile of the furnace.<h4>Summary&nbsp;</h4>Thermo Scientific process mass spectrometers have been successfully monitoring blast furnace off gas at many of the world’s iron and steel companies for over 30 years. For a blast furnace producing 5,000 tonnes a day, a reduction in coke consumption of just 10 kg per tonne of iron produced provides a payback of over $10,000 a day. Users report that the combination of fast, accurate MS gas analysis for gas efficiency, heat and mass balances and hydrogen analysis, with advanced process control and mathematical modeling, has reduced coke consumption by up to 100 kg per tonne and increased iron production. Upgrading to Prima PRO MS can therefore result in complete installation payback within a few weeks.&nbsp;<ul><li>Reduces coke consumption&nbsp;</li><li>Produces consistent quality iron&nbsp;</li><li>Reduces downstream processing costs&nbsp;</li><li>Detects water leaks fast&nbsp;</li><li>Improves thermal control of furnace&nbsp;</li><li>Enables safer operation during blowdown</li></ul>

News from LabRulezGCMS Library - Week 14, 2026

<h3>We're excited to announce that <a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/products/999">Clarity Chromatography Software</a> version 10.1.2 is now available!</h3>This minor update expands Clarity’s portfolio with new control modules.<h4>Newly added Instrument control modules</h4><ul><li>Ecom auxiliary modules</li><li>HTA ICF control modules</li><li>Spark pump</li></ul><h4>Updated Instrument control modules</h4><ul><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/companies/168">Ecom</a> HPLC</li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/companies/328">Knauer</a> HPLC</li><li>Spark ICF control modules</li><li>YoungIn Chromass HPLC</li></ul><blockquote>For a complete list of module changes, see the <a target="_blank" rel="noopener noreferrer" href="https://www.dataapex.com/version_history?product=1">Changelog</a>. For more info about exciting new features directly in Clarity, explore what was introduced in the <a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/article/5622">Clarity 10.1 release highlights</a>.Clarity can control 1000+ instruments; the <a target="_blank" rel="noopener noreferrer" href="https://www.dataapex.com/controls">list can be previewed here</a>.</blockquote><h4>Supported Instruments in Clarity (DataApex) — Quick Guide</h4>Clarity Chromatography Software supports a wide range of chromatographs and peripherals via digital control (DD) and analog acquisition (A/D) using the Colibrick module.<h5>Gas Chromatographs (GC)</h5>Digital integration over LAN/RS232 (many via ICF):<ul><li>Agilent: 5890, 6890, 7890, 8860, 8890, Intuvo 9000</li><li>Shimadzu: GC-2010/2014, Nexis GC-2030</li><li>Thermo Fisher: TRACE 1300/1310</li><li>PerkinElmer: Clarus 400–690</li><li>Also supported: Dani, Ellutia, Young In Chromass, Apix, Fuli, GOW-MAC (selected models)</li></ul><blockquote>Note: Most Agilent 6890–8890 and Intuvo use LAN – ICF.</blockquote><h5>HPLC Systems</h5>Full system/module control:<ul><li>Agilent 1100–1290 Infinity II (ICF)</li><li>Shimadzu LC-10/20 and Nexera LC-40</li><li>PerkinElmer Flexar / NexSAR</li><li>Knauer Azura / BlueShadow / Smartline</li><li>Hitachi Chromaster / Primaide</li><li>Young In Chromass ChroZen series</li><li>Sykam S500–S600, Watrex Streamline, Hanon LC7000–7300</li></ul><h5>HPLC Modules (Pumps, Detectors, Ovens, Fraction Collectors)</h5><ul><li>Pumps: Agilent 1100–1290 families, Knauer, Shimadzu, PerkinElmer, Sykam, SSI, Ecom</li><li>Detectors: VWD/DAD(PDA)/RID/FLD/ELSD across Agilent, Shimadzu, Knauer, PerkinElmer, Young In Chromass, Ecom, etc.</li><li>Column Ovens: Agilent G1316x / G7116x, Shimadzu CTO-20/30/40, Knauer CT2.1, PerkinElmer Flexar</li><li>Fraction Collectors: Knauer FC 6.1, Teledyne FOXY series, Ecom ECF 2096, Waters Fraction Collector II</li></ul><h5>Autosamplers</h5><ul><li>Agilent GC ALS (7673/7683/7693/8697), HPLC ALS modules (G1313A–G7167C)</li><li>Shimadzu AOC-20 / AOC-5000+, SIL-10 / SIL-20 / SIL-40 series</li><li>CTC Analytics PAL, HTA autosamplers, Spark Alias/UHPLC, Knauer AS 6.1L</li><li>PerkinElmer Flexar / NexSAR AS</li></ul><h5>Other Devices</h5><ul><li>GC×GC modulators (e.g., Charles University GC×GC Modulator)</li><li>Valves &amp; switch modules (Agilent, Knauer, Shimadzu, VICI-Valco)</li><li>Degassers, flow monitors, managers, interfaces</li><li>LC-MS / GC-MS: Advion Expression CMS, Microsaic 4500 MiD, Markes BenchTOF (and others)</li><li>Balances (EA extension): Mettler Toledo, Sartorius</li></ul><h5>Analog Acquisition (Colibrick)</h5>A/D support for legacy or analog-output devices:<ul><li>GC: Agilent 5880/4890A, Varian 3xxx/3800/3900, PerkinElmer Clarus series, Thermo TRACE, Shimadzu GC-14/9A, Scion 43x/45x/83xx/85xx, etc.</li><li>HPLC Detectors: Waters 2487/2489, ESA Corona, Hitachi L-series, JASCO FP/UV, Ecom LCD series, many others</li><li>Elemental &amp; Amino Acid Analyzers: Carlo Erba/Costech ECS, Biochrom 20/30+</li></ul>If you are interested in a DEMO VERSION, contact us!

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Agilent Gas Clean carrier gas purifier, CP17973 (New)

Carrier gas purifier designed to remove oxygen, moisture, and hydrocarbons from GC and GC/MS carrier gases, improving system stability and protecting analytical components.

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DataApex Clarity Chromatography software 10.1.2 just released!

Trimming a GC Column: Purpose, Symptoms, and Proper Technique

News from LabRulezGCMS Library - Week 14, 2026