Concerns about injecting water into a GC system largely come from older column designs, where stationary phases were simply coated and could be affected by water exposure. Modern capillary columns are typically chemically bonded, which improves resistance to water injections and even supports water rinsing in many cases.One practical exception involves very polar polyethylene glycol (PEG / “wax”) phases. Because these phases strongly interact with water, repeated aqueous injections can allow water to accumulate and gradually shift selectivity. For many PEG-based columns, minimizing frequent water injections helps maintain consistent performance.A separate—and often more important—issue is water’s very large vapor expansion in a hot inlet. If the vapor volume exceeds the inlet liner capacity, backflash can occur, sending sample vapor into cooler, unheated zones and increasing the risk of carryover. Using smaller injection volumes helps reduce this risk.In workflows where water is the sample matrix (for example, volatile analysis), analytes may elute at relatively low oven temperatures while water and higher-boiling residues can linger. Periodic bake-off (high-temperature cleanup steps) is commonly used to restore column performance when water remains on the phase at low temperatures.In summary, the biggest hesitation about water injections is rooted in legacy, coated column stories. With chemically bonded phases, the key considerations tend to be inlet expansion/backflash behavior, water retention on very polar phases, and routine maintenance practices like bake-out.<blockquote><h4><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/1571">Zebron ZB-WAXPLUS GC Columns</a></h4><ul><li>100% aqueous stable, excellent for aqueous samples; bonded and solvent rinseable</li><li>Extremely inert for acidic compounds</li><li>Enhanced selectivity for low boiling solvents; high retention of alcohols and chlorinated solvents</li><li>Increased efficiency at 20&nbsp;°C</li></ul></blockquote>

Water in GC: Safe or Risky? Here’s What You Need to Know

🎤 Presenter: Paul-Albert Schneide (University of Copenhagen)💾 <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/paper/32780">PDF presentation</a><h3>Abstract</h3>Tensor decomposition methods such as PARAFAC and PARAFAC2 have been proposed for resolving co-elutions, and extracting purified spectra in two-dimensional chromatography datasets. However, the application of these methods is usually restricted to local regions-of-interest (ROIs). Therefore, additional pre-processing steps, are required and processing multiple samples at once can be difficult due to retention time shifts (e.g., it is difficult to define a ROI that captures the same analyse signal in multiple samples).This work presents an application of fast, shift-invariant tensor decomposition, which was used for the decomposition of full-scale GCxGC-VUV datasets. The results show that chemical groups can be resolved, which are non-separable with conventional, template-based approaches, such as aliphates and olefines, Furthermore, the extracted peak areas are in good agreement with the quantitative results of the reference methods (e.g., bromine number for olefines).<h2>Video Transcription</h2><h3>Background and Motivation</h3>The project originated from a collaboration initiated by Alexandra Alvich from IFPEN, who approached Prof. Rasmus Bro’s research group at the University of Copenhagen for help analyzing a GC×GC-VUV dataset acquired during her PhD research. The work was then continued by Paul-Albert Schneider and Jesper Henri from the Technical University of Denmark.The primary objective was to develop a simpler and less manually intensive approach for petrochemical group quantification while maintaining strong quantitative performance and spectral interpretability.According to Schneider, the proposed method is based on two key principles:<ul><li>Simple implementation with a minimal number of tuning parameters</li><li>Accurate estimation of peak patterns, VUV spectra, and peak areas</li></ul>The workflow specifically targets group-level petrochemical analysis rather than individual compound identification.<h3>Data Analysis Workflow</h3>The presented workflow begins with a collection of GC×GC-VUV measurements. In this study, the researchers analyzed:<ul><li>14 gas oil samples</li><li>24 total measurements, including replicates</li><li>Samples processed using different treatment methods</li></ul>Initial preprocessing was performed using a dedicated plug-in module developed during Alexandra Alvich’s PhD work. The preprocessing included:<ul><li>Signal smoothing</li><li>Downsampling</li><li>Basic data conditioning</li></ul>The processed data were then submitted to the decomposition engine developed by the Copenhagen research group. The decomposition produced:<ul><li>Resolved VUV spectra</li><li>GC×GC chromatographic landscapes</li><li>Peak areas or peak volumes</li></ul>An in-house spectral library from IFPEN was subsequently used to verify that the extracted spectra corresponded to known petrochemical groups, enabling group-level quantitative analysis.Importantly, the workflow currently requires only a single major tuning parameter: the number of components used in the decomposition model. The researchers also noted ongoing efforts to automate this selection step.<h3>Comparison with Existing Template-Based Methods</h3>The study benchmarked the new approach against Alexandra Alvich’s previously developed template-based quantification method.In the template-based workflow:<ul><li>Elution regions are predefined using a grid structure</li><li>Peak intensities within those regions are summed</li><li>Quantitative estimates are obtained for specific petrochemical classes</li></ul>Although the template-based strategy demonstrated strong performance compared with other analytical techniques, Schneider highlighted several limitations:<ul><li>Sensitivity to retention time shifts</li><li>Manual adjustment of integration regions</li><li>Dependence on prior knowledge of coeluting compounds</li></ul>The new decomposition-based method was designed to reduce manual intervention and improve robustness against chromatographic variability.<h3>Shift-Invariant Trilinear Decomposition</h3>The proposed workflow is conceptually related to PARAFAC and multivariate curve resolution methods.One important advantage of GC×GC-VUV data is the applicability of the Beer–Lambert law, which enables mathematically structured decomposition approaches.The researchers evaluated two possible strategies:<ol><li>Decomposing each sample individually</li><li>Decomposing all samples simultaneously after concatenation into one large dataset</li></ol>The second strategy became the central focus of the work. Multiple samples were concatenated into a large matrix and factorized to extract shared chemical information across all measurements simultaneously.Unlike many conventional GC×GC deconvolution pipelines, the workflow does not rely on a prior region-of-interest detection step. Instead, the entire dataset is decomposed directly.<h3>Addressing Retention Time Shifts</h3>A critical challenge for PARAFAC-type models is the assumption of strict trilinearity. In GC×GC datasets, however, second-dimension retention time shifts caused by temperature programming violate this assumption.Schneider demonstrated how standard one-component PARAFAC models fail to properly model shifted peaks, leaving characteristic residual patterns. When fitting additional components, conventional models often allocate extra components to describing peak shifts instead of resolving true coeluting compounds.The shift-invariant model solves this issue by explicitly accounting for chromatographic shifts. As a result:<ul><li>Large shifted peaks are modeled correctly</li><li>Residuals are minimized</li><li>Small coeluting peaks become resolvable</li></ul>The algorithm uses fast Fourier transform (FFT)-based operations internally to correct for chromatographic shifts efficiently.According to the presentation, the approach is also significantly faster than PARAFAC2, which is commonly used for shifted datasets.The researchers additionally described extensions of the model that can accommodate:<ul><li>Retention time shifts</li><li>Peak shape variations</li><li>Additional flexibility without losing uniqueness properties</li></ul><h3>Quantitative Results</h3>The team applied a seven-component model to the complete dataset containing 24 GC×GC-VUV measurements.The decomposition extracted seven characteristic VUV spectra, which were compared against the IFPEN in-house spectral library. The extracted spectra matched known petrochemical group signatures very well.The resolved components included:<ul><li>Two monoaromatic components</li><li>Two diaromatic components</li><li>Additional petrochemical group patterns</li></ul>For quantitative evaluation, chemically related components were grouped together.<h4>Reproducibility</h4>Replicate measurements demonstrated strong quantitative reproducibility:<ul><li>Relative standard deviations below 10%</li><li>Consistent peak area estimation across petrochemical groups</li></ul><h4>Comparison with the Template-Based Approach</h4>The decomposition workflow showed good agreement with the existing template-based quantification strategy, with monoaromatics representing the main discrepancy requiring further investigation.Schneider explained that the differences were likely related to relative response factor scaling used in the template-based method but not yet implemented in the decomposition workflow at the time of the presentation.<h4>Future Development</h4>The researchers outlined several next steps for the project:<ul><li>Running models on individual samples to achieve higher resolution</li><li>Resolving sulfur-containing compounds</li><li>Extracting more sample-specific differences</li><li>Automating component number selection</li><li>Investigating deviations in monoaromatic quantification</li><li>Integrating the workflow into an open-source software project</li></ul>The team also expressed interest in future collaboration with other researchers working on related GC×GC data analysis workflows.<h3>Conclusion</h3>The presented shift-invariant trilinear decomposition workflow demonstrated promising performance for automated petrochemical group analysis in GC×GC-VUV datasets. By combining robust mathematical modeling with minimal manual intervention, the method offers a simplified alternative to traditional template-based approaches while maintaining strong quantitative agreement and spectral interpretability.The work highlights the growing role of advanced multivariate data analysis strategies in comprehensive chromatography and demonstrates how shift-aware decomposition methods can significantly improve the analysis of highly complex petrochemical datasets.<blockquote>This text has been automatically transcribed from a video presentation using AI technology. It may contain inaccuracies and is not guaranteed to be 100% correct.</blockquote>

One-shot tensor decomposition of full-scale GC×GC-VUV datasets for resolving petrochemical groups (Paul-Albert Schneide, MDCW 2026)

Our Library never stops expanding. What are the most recent contributions to LabRulezGCMS Library in the week of 11th May 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 note by Shimadzu, poster by MDCW / William &amp; Mary and brochure by Thermo Fisher Scientific!<h3>1. MDCW / William &amp; Mary: Optimizing Solvent Selection and Data Reduction Workflows for GC×GC Fire Debris Analysis</h3><ul><li>Poster</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/labrulez-bucket-strapi-h3hsga3/P_14_O_Brien_63304669ee.pdf">Full PDF for download</a></li></ul><section><div><div><div><div><div><div><h5>What are Ignitable Liquid Residues (ILRs)?&nbsp;</h5><ul><li>Chemical remains of ignitable liquids (IL) (e.g., gasoline or diesel) that did not fully burn during a fire&nbsp;</li><li>ILRs are usually petroleum-based products and contain complex mixtures of volatile chemicals, like hydrocarbons&nbsp;</li></ul><h5>Forensic Analysis of ILRs&nbsp;</h5><ul><li>Collection of porous materials like wood from the fire’s point of origin&nbsp;</li><li>Must be stored in airtight containers to prevent volatile ILR from evaporation&nbsp;</li><li>Passive headspace extraction onto activate charcoal strips (ACS) is used to extract ILRs from debris, and dichloromethane (DCM) is used to extracts ILRs from charcoal strips&nbsp;</li><li>Emerging is the use of two-dimensional gas chromatography – time of fight - mass spectrometry (GC×GC-TOFMS), with higher separation and resolution</li><li>Resulting chromatograms presents a pattern of peaks which can be used to identified specific type of accelerant used&nbsp;</li></ul><h5>Chemometrics&nbsp;</h5><ul><li>The discipline that focuses on the application of statistical and mathematical methods to analyze chemical data and extract meaningful information (Bovens, 2019)&nbsp;</li><li>Helps make sense of large datasets from analytical instruments, find pattens, and classify samples</li></ul><h4>Methods</h4><h5>Analytical Instrumentation&nbsp;</h5><ul><li>LECO corporation <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/1097">BTX4D GC×GC-TOFMS</a> with <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/1289">Paradigm Shift reverse fill-flush (RFF) flow modulator</a></li></ul><h5>Software&nbsp;</h5><ul><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/1873">ChromaTOF Sync 2D</a> (LECO corporation)&nbsp;</li><li>R Statistical Software</li></ul><h4>Conclusions</h4>This study demonstrated that the use of chemometrics can be integrated into a data processing workflow to better understand data sets and create a streamlined process. Using UMAP, patterns identified that were not originally seen in PCA lead to the preferred solvents of ILR extraction being hexane and methanol. Since UMAP allowed visualization of local and global structures, groupings of gasoline samples allowed for better analysis of solvent effect.<h3>2. Shimadzu: Multiresidue Pesticides Analysis in Solvent Extract of Annatto (Natural Color Additive) Using <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=1&amp;search=GCMS-TQ8050+NX">GCMSTQ8050 NX</a></h3><ul><li>Application note</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/labrulez-bucket-strapi-h3hsga3/an_06_sip_gc_043_en_95576a9ac4.pdf">Full PDF for download</a></li></ul><h5>User Benefits</h5><ul><li>&nbsp;Accurate and reproducible trace level quantitation of pesticides in highly pigmented complex matrix using Ultra-fast GCMSTQ8050 NX and QuEChERS extraction</li><li>Single-laboratory partial validated method for LOQ determination meeting regulatory guidelines</li><li>Ease of instrumental method optimization using GCMS Smart Pesticides Database Ver.2 from Shimadzu Corporation</li></ul>Annatto is an orange-red condiment and food colorant derived from the seeds of the achiote tree (Bixa Orellana) (Fig. 1). It is often used to impart a yellow to red-orange color to foods, but sometimes also for its flavor and aroma. Similar effects can be obtained by extracting some of the color and flavor principles from the seeds, which are then added to the food. Annatto and its extracts are now widely used in an artisanal or industrial scale as a coloring agent in many processed food products, such as cheeses, butter, baked goods, potatoes, snack foods, breakfast cereals, smoked fish etc. In these uses, Annatto is a natural alternative to synthetic food coloring compounds.&nbsp;Owing to its large culinary uses and other diverse applications, use of chemical pesticides for its production in large quantities is imperative. Dye extraction process may result in concentration of pesticides and in turn contribute to adverse impact on human health when incorporated in various preparations. Hence quantitation of residual pesticides in Annatto extract becomes very important. As the oleoresin is a complex matrix, it is required to develop a rugged, sensitive and efficient method for extraction of residual pesticide and its analysis.&nbsp;This study reports a highly sensitive method for simultaneous quantification of multiple pesticides in highly pigmented complex matrix of Annatto using modified QuEChERS[1] with triple quadrupole gas chromatography (GC-MS/MS) system.<h4>Materials and Methods</h4>For this study, customized reference standard mixture of most commonly observed pesticides in Annatto seeds was procured from Restek Corporation.The calibration standards were analyzed from 0.5 to 1000 μg/L. Linearity was plotted by external standard method and using weighted regression of 1/C2. Sample was spiked at 3 levels i.e., 10, 25 and 100 μg/kg. Recovery samples were prepared in 6 replicates at each level. <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=1&amp;search=GCMS-TQ8050+NX">GCMS-TQ8050 NX</a> (Fig. 2), manufactured by Shimadzu Corporation Japan, was used for quantitation. LabSolutions InsightTM was used for data processing, which helped in evaluating validation parameters with ease.<h4>Conclusion</h4>This study shows that the modified QuEChERS method combined with GC-MS/MS system is a reliable and efficient tool to quantify residual pesticides in Annatto extract sample. Although Annatto extract is a highly pigmented complex matrix, the modified QuEChERS method significantly reduces interference. Also, extremely sensitive Shimadzu GC-MS/MS allows trace level detection even after multifold dilution of sample. This helps in reducing contamination and enhancing ruggednessresulting in reproducible detection of analytes.<h3>3. Thermo Fisher Scientific: Sentinel PRO 710 environmental mass spectrometer Precise real time gas analyzer for toxic volatile organic compounds</h3><ul><li>Product specification</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/labrulez-bucket-strapi-h3hsga3/sentinel_pro_710_spec_sheet_en_886523bfc2.pdf">Full PDF for download</a></li></ul>The <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=3&amp;search=Sentinel+PRO">Thermo Scientific™ Sentinel PRO Environmental Mass Spectrometer </a>is a highly reliable and versatile gas analyzer ideal for reporting the presence of toxic VOCs from fugitive emissions in industrial settings to ensure worker safety.<h4>Fugitive emissions of toxic VOCs&nbsp;</h4>Wherever there is potential danger for fugitive emissions of toxic organic vapors from a chemical production unit, regulating authorities often require plants to keep records of ambient vapor concentrations to protect workers from exposure. Various forms of capture include evacuated vessels, organic vapor monitors, or purge and trap devices, all of which require samples to be sent for analysis. Alternatively, electrochemical sensors or open path FT-IR spectroscopy can provide more immediate results. However, none of these technologies are capable of providing the spatial and temporal resolution required to qualify as actionable information.&nbsp;<h4>Analytical platform&nbsp;</h4>The primary feature of the Sentinel PRO mass spectrometer is the magnetic sector analyzer. This field-proven technology has demonstrated the strongest performance for industrial on-line gas analysis. Magnetic sector technology offers precision, accuracy, long intervals between calibrations. The new touchscreen interface further enhances usability, providing intuitive in-person operation, simplified maintenance, and real-time data viewing. Multi-role user permissions ensure security and control allowing operators to customize settings based on their specific needs.&nbsp;<h4>Comprehensive data collection&nbsp;</h4>With speed and precision, the Sentinel PRO analyzer monitors all the critical areas for short-term exposure levels of toxic VOCs, and also provides accurate and time-weighted average exposure data. With a high number of sample points available, many can be located close to potential leak points such as valve stems, etc., enabling leak detection and correction before any toxic hazard is created.&nbsp;<h4>Membrane inlet mass spectrometry&nbsp;</h4>The analyzer is fitted with a membrane inlet to reduce the pressure of the sample air from atmospheric to the working pressure of the enclosed ion source. This allows a method of sample introduction that greatly enhances the system’s sensitivity to VOCs. Since the membrane is more permeable to VOCs than to major air gases, it provides enrichment by several orders of magnitude, enabling detection as low as 5 ppb (species dependent) permits easy membrane replacement during annual routine maintenance to minimize downtime and increase productivity.</div></div></div></div></div></div></section>

News from LabRulezGCMS Library - Week 20, 2026

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LECO Paradigm Flow Modulator and Shift Flow Splitter

Paradigm RFF Flow Modulator with Shift Flow Splitter boosts GC×GC peak capacity while maintaining constant MS/FID split ratios, enabling accurate, repeatable quantitation across full volatility ranges.

The Paradigm Flow Modulator with Reverse Fill-Flush (RFF) technology dramatically expands chromatographic peak capacity across the full volatility range while preserving quantitative accuracy. The RFF modulator fills a fixed-volume sample loop with effluent from the first-dimension column and then rapidly flushes it onto an orthogonal second-dimension stationary phase. This true comprehensive GC×GC transfer ensures excellent repeatability, robust quantitation, and high-quality separations for complex samples.<h3>Key features</h3><ul><li>Reverse Fill-Flush (RFF) modulation for true comprehensive GC×GC with complete analyte transfer</li><li>Novel chromatography splitter with two channels of pressure assistance</li><li>Designed for high flows required for RFF modulation (≈20 mL/min)</li><li>Constant MS/FID split ratio maintained throughout the entire run, including oven temperature ramps</li></ul><h3>ChromaTOF makes modulation simple</h3>Paradigm eliminates complex offline flow calculations. Integrated <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/41">ChromaTOF® software</a> automatically performs all required calculations via a straightforward interface. The resulting methods are optimized to deliver complete analyte transfer, excellent peak shapes, and high chromatographic resolution—without manual trial-and-error.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/LECO_Chromatof_flow_calculation_6b8ca60f99.jpg" alt="LECO Paradigm Flow Modulator and Shift Flow Splitter: ChromaTOF Software identifies method calculation improvements for RFF modulation" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_LECO_Chromatof_flow_calculation_6b8ca60f99.jpg 245w," sizes="100vw" width="670" height="426"><h3>A shift forward in chromatographic analyses</h3>The Shift Flow Splitter introduces a novel splitting mechanism that maintains a constant split ratio between MS and FID across the full GC oven program. Compared to traditional splitters, Shift delivers superior quantitative accuracy with minimal internal standardization, greatly simplifying compound-level and group-type quantitation in GC and GC×GC workflows.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/LECO_LECO_Paradigm_G_Cx_GC_prutokovy_modulator_a_Shift_splitter_5_245c7c2fde.jpg" alt="LECO Paradigm Flow Modulator and Shift Flow Splitter: Close-up on the Shift Flow Splitter installed in a GC oven" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_LECO_LECO_Paradigm_G_Cx_GC_prutokovy_modulator_a_Shift_splitter_5_245c7c2fde.jpg 245w," sizes="100vw" width="2925" height="825"><h3>Software-optimized detector performance</h3>ChromaTOF automatically balances and optimizes the flow directed to TOFMS and FID, ensuring proper peak shapes and matched sensitivity for reliable qualitative and quantitative results.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/LECO_Optimize_flow_e51d505415.jpg" alt="LECO Paradigm Flow Modulator and Shift Flow Splitter: ChromaTOF Software automatically optimizes flow rates" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_LECO_Optimize_flow_e51d505415.jpg 207w," sizes="100vw" width="808" height="608">

LECO QuadJet™ SD

GC×GC-FID system combining thermal modulation and ChromaTOF software to reduce coelution bias, boost resolution, and deliver accurate quantitation of complex samples—without sacrificing productivity.

The QuadJet SD is a comprehensive GC×GC-FID solution designed to reveal the true chemical composition of complex real-world samples. By combining the universal sensitivity of flame ionization detection (FID) with the dramatically increased chromatographic resolution of comprehensive two-dimensional gas chromatography (GC×GC), QuadJet SD minimizes coelution-driven bias and delivers a far more accurate representation of sample composition than conventional one-dimensional GC.Unlike straight GC-FID, where unresolved peaks inflate detector response and introduce systematic error, GC×GC separates compounds using two orthogonal mechanisms within a single run. True GC×GC instruments—such as the QuadJet SD from LECO—use active modulation to quantitatively slice the effluent from the first column and refocus it onto the second column. This approach preserves quantitative integrity while unlocking orders-of-magnitude gains in peak capacity and signal-to-noise ratio.<h3>Key Benefits</h3><ul><li>Enhanced separation power for highly complex mixtures</li><li>Reduced noise and bias error compared to conventional GC-FID</li><li>Integrated <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/41">ChromaTOF-based software</a> for acquisition, processing, classification, and reporting in one environment</li><li>Classification tools that simplify component identification</li><li>Cryogen-free modulation option eliminates the need for liquid nitrogen dewars</li></ul><h3>Theory of Operation</h3>In GC-FID analysis, compound quantitation relies on peak area. As sample complexity increases—diesel fuels being a classic example with thousands of constituents—the likelihood of coelution rises sharply. Coeluting compounds produce artificially elevated FID responses, leading to high-bias errors.GC×GC overcomes this limitation by performing two independent chromatographic separations in a single experiment. Thanks to the orthogonal selectivity of the two columns, compounds that coelute in the first dimension are efficiently separated in the second. In the QuadJet SD, eluting peaks from the primary column are quantitatively segmented by the modulator and cryo-focused before entering the secondary column, generating extremely narrow second-dimension peaks—often as short as 50 ms—while maintaining accurate quantitation.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/LECO_Quad_Jet_SD_2_bbb51b2254/LECO-QuadJettm-SD-2_l.webp" alt="LECO: QuadJet™ SD 2 – Processing of acquired GC×GC data using LECO ChromaTOF software" width="923" height="543"><h3>Thermal Modulation</h3>Thermal modulation represents the highest-performance approach for GC×GC, and LECO’s implementation sets the benchmark for ruggedness, reliability, and analytical performance. The QuadJet SD employs a dual-stage, quad-jet thermal modulator positioned between the two columns. This design enables on-column cryo-focusing, dramatically improving peak detectability and resolving power, and delivering an order-of-magnitude improvement in signal-to-noise.For laboratories seeking lower operating costs and simplified workflows, a consumable-free thermal modulator (no liquid nitrogen) is available. This option maintains excellent performance for moderately volatile compounds while eliminating cryogen handling.<h3>Modulators and Instrument Options</h3><ul><li>Thermal modulator choices:<ul><li>Liquid-nitrogen-cooled thermal modulator</li><li>Consumable-free thermal modulator</li></ul></li><li>Optional inlets: S/SL, PTV, and MMI</li></ul>Designed with productivity in mind, the QuadJet SD combines ease of use with an industry-leading secondary oven for the second-dimension column. For laboratories ready to move beyond conventional GC and truly see what has been hidden by coelution, QuadJet SD delivers the next dimension in analytical insight.

LECO ChromaTOF® Tile analytical software

ChromaTOF Tile enables rapid, statistically robust GC×GC-TOFMS data comparison using tiled heatmaps, reducing false positives and cutting data mining from days to minutes.

Turn Your Data into ChemistryThe volume of GC×GC-TOFMS data can quickly become overwhelming. Thousands of analytes across multiple tables may require months of pixel-level data mining, often complicated by false positives caused by normal chromatographic variation.ChromaTOF Tile fundamentally changes how GC×GC data are compared and interpreted. Instead of evaluating individual pixels, the software statistically compares tiled regions of chromatograms. Truly significant differences rise immediately to the surface—allowing you to focus on chemical meaning rather than data hunting.<blockquote>“ChromaTOF Tile is an enabling technology that has reduced our peak picking time from 10 days to 10 minutes.”</blockquote><h3>Designed for Sample Group Differentiation</h3>Integrated heatmap tables provide instant visual feedback on relative intensities and variance. ChromaTOF Tile highlights differences between two or more sample classes, including:<ul><li>Biomarkers distinguishing healthy vs. diseased samples</li><li>Off-odor detection in food quality control</li><li>Environmental samples upstream/downstream of contamination sources</li><li>Petroleum samples from different geographic origins</li><li>Any complex GC×GC comparison where class differentiation matters</li></ul><h3>Key Features</h3><ul><li>Stand-alone software designed to work in conjunction with <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/41">ChromaTOF</a></li><li>Rapid statistical comparison of GC×GC data sets</li><li>Exportable tables and plots for efficient reporting</li><li>Clean, library-searchable spectra generated from tiling</li><li>Approximate trend quantification using tile areas</li><li>Reduced false positives from chromatographic misalignment</li></ul><h3>Theory of Operation</h3>The challenge: Comparing large sets of GC×GC chromatograms is slow and alignment-sensitive, often taking weeks or months even with automated tools.The solution: In collaboration with Robert Synovec, ChromaTOF Tile applies Fisher ratios to partition chromatograms into regions (“tiles”). Instead of pixel-by-pixel comparison, corresponding tiles are averaged and statistically evaluated.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/LECO_Chroma_TOF_Tile_analytical_software_816a8a7705.jpg" alt="LECO ChromaTOF® Tile analytical software" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_LECO_Chroma_TOF_Tile_analytical_software_816a8a7705.jpg 245w," sizes="100vw" width="854" height="462">The result is a set of intuitive heatmaps that immediately direct attention to regions of high variance and high analytical relevance—without altering the underlying data.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/LECO_Chroma_TOF_Tile_analytical_software_2_c3c8abd476.jpg" alt="LECO ChromaTOF® Tile analytical software" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_LECO_Chroma_TOF_Tile_analytical_software_2_c3c8abd476.jpg 245w," sizes="100vw" width="1045" height="566">

LECO GCxGC FLUX flow modulator

Flux GC×GC flow modulator simplifies GC×GC analysis using diverting flow principles. It offers robust, cost-effective modulation without cryogens, ideal for complex, concentrated samples.

Our innovative Flux GC×GC flow modulator was designed with one goal in mind—to make GC×GC more routine, accessible, and easier for you. The flow modulator's concept is based on the sound and easily understood principles first articulated by Seeley et al. on diverting flow. This extraordinarily simple design comprising of a cross shape and sideways T, is not only easy to setup and get started, but its ease-of-use makes it the most cost-effective option for GC×GC analysis.This flow-based modulator is perfect for those who want to perform robust GC×GC analysis, but who don't need the sensitivity of standard quad jet thermal modulation. Ideal samples should be complex, but relatively concentrated. Appropriate applications include petroleum and fragrance analyses such as the classic weathered crude oil example pictured below, which shows a GC×GC plot generated on our Pegasus® BT platform using the Flux flow modulator.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/ee943ea0acb34a8d9c5b72e7ace10666/obrazek_l.webp" alt="LECO GCxGC FLUX flow modulator" width="957" height="523"><h4>Theory of Operation: Diverting Flow</h4>The first and secondary capillary columns are connected together through a simple tube with a fixed gap between the columns. A flow of gas (helium) is then used to inject into the second column or divert to waste. The precision timing and flows are all handled by our integrated software, therefore you just have to click one button to setup and begin performing flow modulation GC×GC on our Pegasus BT platform.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/508b477dd1604d15855f26d786d5b1e4/obrazek_l.webp" alt="LECO GCxGC FLUX flow modulator" width="1026" height="488">Furthermore, no complex spreadsheets are needed to understand your method. This simple and robust design does not require cryogens to carry out GC×GC, which saves time and boosts efficiency in your lab.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/6796d4581c894291b9fab0088753cb8b/obrazek_l.webp" alt="LECO GCxGC FLUX flow modulator" width="918" height="545">

LECO QUADJET Thermal Modulator

Consumable-free dual-stage thermal jet modulator for GC×GC delivering on-column cryo-focusing, higher peak detectability, superior separation, and reliable performance without liquid nitrogen.

The QUADJET Thermal Modulator from LECO delivers industry-leading performance for comprehensive two-dimensional gas chromatography (GC×GC). Compared to alternative thermal or valve-based modulators, QUADJET stands out for its exceptional ruggedness, long-term reliability, and superior modulation efficiency.This GC×GC modulation system uses a dual-stage thermal jet modulator positioned between the first- and second-dimension columns. The design enables true on-column cryo-focusing, significantly enhancing peak sharpness, detectability, and separation power—especially for co-eluting compounds in complex sample matrices.<h3>Key benefits</h3><ul><li>Highest modulation performance for GC×GC Enhances peak detectability and improves separation of co-eluting compounds.</li><li>Dual-stage thermal jet design Provides efficient trapping and re-injection between columns.</li><li>On-column cryo-focusing Improves sensitivity and separation of closely eluting analytes.</li><li>Exceptional robustness and reliability Designed for routine, long-term GC×GC operation.</li></ul><h3>Thermal modulation without liquid nitrogen</h3>Unlike traditional cryogenic modulators, the QUADJET thermal modulator is consumable-free. It delivers the full performance benefits of thermal modulation without the need for liquid nitrogen, eliminating cryogen costs, logistical complexity, and downtime—while maintaining consistent, high-quality results.The QUADJET Thermal Modulator is an ideal choice for laboratories seeking maximum GC×GC performance with minimal operational burden, particularly in demanding applications involving highly complex samples.

LECO Simply GC×GC®

Simply GC×GC from LECO guides users through the steps of creating an optimized GC×GC method or converting an existing 1D GC method for complex samples.

Simply GC×GC from LECO is a free tool designed to walk users through the steps of creating an optimized GC×GC method for complex samples.The tool allows users to create a GC×GC method from scratch or convert an existing 1D GC method to GC×GC.Simply GC×GC provides logical, step-by-step instructions, for example for:<ul><li>setting the secondary oven offset,</li><li>setting the second-dimension column length,</li><li>experimentally evaluating stationary phases and peak capacity.</li></ul>Simply GC×GC takes a simple approach to GC×GC and helps users avoid unnecessary testing while streamlining the method development cycle.

ARC GCxGC Xpansion

ARC’s simple stop-flow modulator can be installed in minutes and turn any GC into a powerful multi-dimensional separation machine. ARC’s modulator emphasizes robustness, simplicity, and ease of use to allow anyone from a novice GC user to a veteran expert to generate valuable chemical data on the most complex samples. 

<h3>No-fuss GCxGC solution</h3>
This affordable package includes free, open-source software (visualization only), and ARC’s lifetime support. For power users we offer GC Image software. 
<h3>Why choose us?</h3>
<ul>
<li>Affordable</li>
<li>Robust design</li>
<li>Simple and easy self-installation or professional installation</li>
<li>Dramatically increased peak capacity</li>
<li>Easily switch between 1D and 2D GC</li>
<li><a href="https://www.activatedresearch.com/gcxgc_vis/">Free visualization software</a></li>
</ul>
<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/ARC_ARC_G_Cx_GC_Xpansion_9536cf0985/ARC-ARC-GCxGC-Xpansion.jpg" alt="ARC: ARC GCxGC Xpansion solution"/>
<h3>Why should I use GCxGC?</h3>
The separation of compounds by gas chromatography is typically performed using a single analytical column. As samples become more complex, it can become difficult to separate all the compounds from each other and they can start to overlap, or co-elute. Longer or narrower columns can be used to increase resolving power, but with diminishing returns.
Comprehensive two-dimensional GC, or GCxGC, drastically increases separation power by adding a second analytical column after the first column. A modulator placed between the two columns pulses the analytes from the first column onto the second column. When the columns are orthogonal in separation power, this technique can result in an order of magnitude increase in the number of analytes that can be detected.
ARC’s solution takes advantage of stop-flow modulation to make GCxGC an attainable configuration for any analytical laboratory. It involves continually sampling the effluent from the first column into an accumulator tube and re-injecting it onto a second, smaller column with orthogonal separation. This second separation happens in the time it takes to accumulate the next sample. The pulse time is known as the modulation time.

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