🎤 Presenter: Christopher Freye (Los Alamos National Laboratory)💾 <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/labrulez-bucket-strapi-h3hsga3/O_1_Freye_10783a9cf3.pdf">PDF presentation</a><h3>Abstract</h3>Two-dimensional gas chromatography (<a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?instrumentationItems=2">GC×GC</a>) when coupled with mass spectrometry (MS) especially high-resolution mass spectrometry (HRMS) provides the ideal technique to discover minute chemical changes. However, GC×GC analyses result in extremely large datasets (GBs of information) wherein the statistically significant chemical changes are buried within the background chemical matrix. To combat these issues, many chemometric techniques have been developed or applied. Recently we introduced a new chemometric technique for GC-MS termed alteration analysis (ALA) and two-dimensional correlation (2DCOR) which can be used to discover statistically significant chemical changes across a series of chromatograms and understand the relationship between the statistically relevant changes. ALA generates three sets of information, the basic alteration map (BAM) which is the magnitude of the change, the synchronous alteration map (SAM) which describes the linear change, and the asynchronous alteration map (AAM) which describes the non-linear change. 2DCOR can then be used to understand the relationship between the chemical changes but 2DCOR can also resolve the sequence of the changes. A workflow for GC×GC-MS will be demonstrated. Special attention will be given to what differentiates the GC×GC work flow from GC for both the ALA and 2DCOR.<h3>Video Transcription</h3>The presentation focuses on how advanced mathematical and chemometric methods can be used to extract meaningful information from highly complex chromatographic data, especially in multidimensional chromatography coupled with mass spectrometry (GC×GC-MS, LC-MS).<h4>Why traditional data analysis falls short</h4>Modern multidimensional chromatography generates extremely large datasets, often containing billions of data points. Visual inspection, peak tables, or classical identification-based workflows are impractical—especially when:<ul><li>Samples are highly complex (e.g. petroleum, metabolomics, high explosives)</li><li>Most compounds are unknown unknowns</li><li>The key question is not what the compounds are, but whether samples differ and how</li></ul>Program managers and decision-makers are primarily interested in detecting statistically significant changes, not exhaustive compound identification.<h4>Introduction of Alteration Analysis (ALA)</h4>To address subtle, trend-based changes across series of chromatograms, the speaker introduces Alteration Analysis (ALA), a chemometric approach adapted from spectroscopy and applied to chromatography.ALA quantitatively evaluates how individual data points change across multiple samples, allowing detection of:<ul><li>Extremely subtle trends</li><li>Overlapping peaks</li><li>Changes hidden in noise or baseline interference</li></ul>Key ALA outputs include:<ul><li>BAM (Basic Alteration Map): magnitude of change</li><li>SAM (Systematic Alteration Map): linear changes</li><li>AM (Alteration Map): nonlinear changes</li></ul>Even changes as small as 1% per sample can be detected reliably, including peaks that are heavily overlapped.<h4>Beyond detection: understanding relationships with 2D Correlation</h4>Once statistically significant changes are identified, two-dimensional correlation analysis (2D-COR) is used to understand relationships between changing compounds, including:<ul><li>Whether compounds are correlated or anti-correlated</li><li>The sequence of changes over time (which changes happen first)</li></ul>This is especially critical for degradation and aging studies, where intermediate species may appear and disappear before the final state—information that traditional methods like Fisher ratio or PCA often miss.<h4>Solving GC×GC challenges with tiling</h4>GC×GC data introduces additional challenges due to:<ul><li>Peak misalignment</li><li>Exponential data growth during correlation calculations</li></ul>The presenter explains how tile-based approaches reduce data dimensionality, overcome alignment issues, and make ALA and 2D correlation computationally feasible—even for massive GC×GC-MS datasets.<h4>Real-world application: explosive aging studies</h4>The methodology was applied to aging and decomposition of high explosives, where:<ul><li>Over 250 chemical changes were identified</li><li>Many intermediate species would have been missed using traditional comparisons</li><li>ALA combined with 2D correlation enabled reconstruction of degradation pathways</li><li>The most significant change was not necessarily the first change, a critical insight for risk assessment and stability studies</li></ul><h4>Key takeaway</h4>By combining Alteration Analysis and 2D correlation, the approach:<ul><li>Detects statistically guaranteed chemical changes</li><li>Handles subtle, overlapped, and noisy signals</li><li>Determines magnitude, type, interrelationships, and order of changes</li><li>Shifts chromatographic data analysis from identification-driven to decision-driven</li></ul>This math-driven workflow enables faster, more reliable interpretation of complex chromatographic datasets and provides actionable insights for applications such as explosive aging, pharmaceutical degradation, and complex mixture analysis.<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>

Discovery analysis for GCxGC trends using alteration and 2D correlation (Chris Freye, MDCW 2026)

Our Library never stops expanding. What are the most recent contributions to LabRulezGCMS Library in the week of 9th February 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 technical note by Agilent Technologies, presentation by MDCW / University of Copenhagen and application notes by Shimadzu and Thermo Fisher Scientific!<h3>1. Agilent Technologies: What Causes Spots on <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?instrumentationItems=19&amp;manufacturerItems=1&amp;search=PLOT">PLOT Columns</a>? Will It Affect the Performance of the Column?</h3><ul><li>Technical note</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/labrulez-bucket-strapi-h3hsga3/te_what_causes_spots_plot_columns_affecting_performance_5994_8775en_agilent_3b7180512a.pdf">Full PDF for download</a></li></ul>Spots on porous layer open tubular (PLOT) columns are caused by small voids in the stationary phase coating inside the tube. These spots are areas where there is an uneven coating or lack of phase. It is normal to find some voids in the phase coating of PLOT columns. The stationary phase in PLOT columns is an opaque, solid, and porous material. In many Agilent PLOT columns such as the GS-Alumina phases, molecular sieves, porous polymers (Q and U), and the GS-OxyPLOT, the stationary phase is visible as a white powder. For many PLOT columns, the stationary phase fill solution is a viscous suspension of particles that are less than 10 microns in diameter. The phase is coated using a dynamic process in which a plug of fill solution is pushed through the tubing, and the plug’s speed and viscosity determines the thickness of the stationary phase layer. Once the PLOT’s stationary phase is deposited, it is held in place by electrostatic charge, chemical interactions between particles, and/or binding agents. In wall‑coated open tubular (WCOT) columns, stationary phases such as polysiloxanes or polyethylene glycols are immobilized by chemical bonding to the glass surface and cross-linking between polymer strands. Because this type of bonding and cross‑linking is not possible with PLOT phases, the result is a stationary phase layer that is both fundamentally different and inherently less stable in PLOT columns than in WCOT&nbsp;columns.<h3>2. MDCW / University of Copenhagen: One-shot tensor decomposition of full-scale GC×GC-VUV datasets for resolving petrochemical groups</h3><ul><li>Presentation</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/labrulez-bucket-strapi-h3hsga3/O_17_Schneide_67c8ff7866.pdf">Full PDF for download</a></li></ul>The presentation introduces a novel all-samples-at-once, shift-invariant tri-linear tensor decomposition approach for the analysis of full-scale <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?search=GC%C3%97GC-VUV">GC×GC-VUV</a> datasets, aimed at resolving and quantifying petrochemical groups. Traditional template-based or pixel-based methods struggle with retention-time shifts and co-eluting compounds, often requiring manual intervention and prior chemical knowledge. The proposed approach leverages the intrinsic low-rank structure of GC×GC-VUV data to enable robust, automated group-level analysis across multiple samples simultaneously.At the core of the method is a shift-invariant tri-linear model, conceptually related to PARAFAC and multivariate curve resolution, but extended using frequency-domain (FFT-based) modeling to explicitly account for chromatographic peak shifts. By decomposing the entire dataset in one step, the model provides accurate estimates of peak landscapes, VUV spectra, and relative peak areas, while remaining agnostic to retention-time variability. Importantly, the approach requires only a small number of tunable parameters, making it practical for routine use.The method was demonstrated on a case study involving 14 petrochemical gas-oil samples, including straight-run, hydrotreated, hydroconverted, coker, and light cycle oils. Extracted VUV spectra showed excellent agreement with reference spectra from a VUV spectral database, enabling confident assignment of components to chemical groups such as saturates, olefins, and mono- to poly-aromatics. Quantitative results exhibited high repeatability (RSD typically 3–9%) and strong correlation with established template-based reference methods.Overall, the work demonstrates that one-shot, shift-invariant tensor decomposition provides a powerful and scalable alternative to conventional GC×GC data-analysis strategies. By combining chemical interpretability, robustness to chromatographic shifts, and strong quantitative performance, the approach opens new opportunities for automated, high-confidence group-level analysis of complex petrochemical samples and beyond.<h3>3. Shimadzu: Py-Screener Ver. 3: Simultaneously Test for Substances Regulated Under RoHS, TSCA, and POPs</h3><ul><li>Application note</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/labrulez-bucket-strapi-h3hsga3/an_01_00949_en_4754e50164.pdf">Full PDF for download</a></li></ul><h5>User Benefits</h5><ul><li>In just one analysis, <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?manufacturerItems=3&amp;search=Py-Screener">Py-Screener</a> Ver. 3 can determine levels of phthalate esters, brominated flame retardants (PBBs, PBDEs), PIP (3:1), UV-328, dechlorane plus (DP), short-chain chlorinated paraffins (SCCPs), and medium-chain chlorinated paraffins (MCCPs).&nbsp;</li><li>It can also test for SCCPs and MCCPs by electron ionization (EI) instead of negative chemical ionization (NCI).&nbsp;</li><li>PIP (3:1), UV-328, DP, and SCCPs and MCCPs can be screened without the need for corresponding reference materials.</li></ul>Countries and regulatory bodies worldwide are introducing increasingly stringent regulations on the chemical substances used in electronic devices and industrial products. The RoHS Directive and REACH regulations in the EU, the Toxic Substances Control Act (TSCA) in the USA, and the Stockholm Convention on Persistent Organic Pollutants (POPs) are also targeting an increasingly broad range of substances. Therefore, manufacturers are required to accurately identify regulated substances in their products and comply with each regulation. While Py-Screener Ver. 2 can screen for seven phthalate esters and brominated flame retardants, including substances regulated under the RoHS Directive, version 3 can also screen for PIP (3:1), which is regulated under the TSCA, as well as UV328, DP, and SCCPs and MCCPs , which are regulated under the Stockholm Convention on POPs. A list of supported substances isshown in Table 1. This article introduces the simultaneous analysis of multiple regulated substances and a case study of testing specific regulated substances in samples, using Py-Screener Ver. 3.<h4>Analysis Process</h4>Py-Screener Ver. 3 can determine levels of phthalate esters and brominated flame retardants contained in products in accordance with the international analytical standards IEC62321-8 and IEC62321-3-3. It can also test for specific regulated substances (Table 1) under the same conditions and in the same analysis. In this test, background intensity and instrument sensitivity (S/N) were verified before analyzing samples. These parameters are prescribed by IEC62321-8 to ensure the accuracy of the methods used. Background intensity and instrument sensitivity were determined using a reference material (PN: 225-31003- 91) *1 that consisted of a plastic sheet that was spiked with seven phthalate esters. The results met the criteria for both parameters.The testing workflow is shown in Fig. 1. Before testing samples, calibration curves were prepared by analyzing the 1000 mg/kg phthalate ester reference material and polypropylene spiked with brominated flame retardants (ERM-EC591). A hole puncher was used to punch out two discs at a time of the phthalate ester reference material, and a cutter was used to obtain pieces of the other materials. Each material was weighed in a sample cup for analysis. During the analysis of samples, phthalate esters and some of the regulated brominated flame retardants were quantitated using a one-point calibration curve. The remaining brominated flame retardants and specific regulated substances were quantitated using the correction factor database*2 that is included with Py-Screener Ver. 3.<h4>Conclusion</h4>Py-Screener Ver. 3 successfully determined in samples the concentrations of the regulated substances PIP (3:1), UV-328, DP, and SCCPs and MCCPs. Normally, SCCP and MCCP levels are tested using NCI, but Py-Screener Ver. 3 uses EI. This enables it to test for not only SCCPs and MCCPs but also phthalate esters, brominated flame retardants, and other regulated substances in just one analysis. In addition, by using the relative correction factors linked to DEHP in the phthalate ester reference material, the levels of these regulated substances were determined without the need for the corresponding reference materials. Py-Screener Ver. 3 can also create a screening program that addresses substance restrictions under the RoHS Directive, the US TSCA, and the POPs Convention.<h3>4. Thermo Fisher Scientific: Improving low carbon steel production in specialty steel processes</h3><ul><li>Application note</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/labrulez-bucket-strapi-h3hsga3/prima_pro_process_mass_spectrometer_an1626_7fc840235f.pdf">Full PDF for download</a></li></ul>World crude steel production reached 1,691 million tonnes in 2017, up by 5.3% compared to 2016.1 While much of this capacity is still produced in primary steel processes such as basic oxygen furnaces and electric arc furnaces, the need for refined steel with greater durability and resistance to heat and corrosion has led to the increased use of vacuum degassing processes, such as VOD and RH, in secondary steel production. These processes are able to achieve ultra-low levels of residual carbon, while at the same time retaining desired levels of other alloy materials. If these processes are to achieve the required level of steel product quality, they need fast, continuous gas analysis of the furnace exhaust gas. Without accurate information on the composition of the gas leaving the furnace, any variations in the decarburization process are only detected after the event, resulting in the production of out-of-specification steel.<h4>Advantages of mass spectrometry&nbsp;</h4>Traditional Non-Dispersive Infra-Red (NDIR) analyzers are used in many conventional steelmaking processes to measure CO and CO2 , but they can only sample at atmospheric pressure. In vacuum steelmaking the process pressure changes dramatically, typically from atmospheric pressure down to less than 1 mbar, over the 20-30 minutes of the melt. So NDIR analyzers have to sample some distance downstream from the process. Analytical data is updated several minutes after the gas leaves the melt and the control system is forced to operate on historic rather than real-time data.&nbsp;Paramagnetic analyzers can be used to measure O2 , while thermal conductivity analyzers can be used to measure H2 . These analyzers also suffer from slow response, while the need to operate three different types of analyzers adds to the plant maintenance burden. Moreover, the three analyzers cannot analyze inert gases, so N2 is calculated by difference, a result that suffers from the sum of the errors of the three analytical techniques.&nbsp;Mass spectrometry operates at high vacuum so it is ideal for monitoring vacuum processes. It is also able to monitor all seven components in Table 1 in seconds rather than minutes, ensuring the plant control model is frequently updated with accurate compositional data.<h4>Precision of analysis&nbsp;</h4>At the heart of the <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?manufacturerItems=2&amp;search=Prima+PRO+Mass+Spectrometer">Thermo Scientific™ Prima PRO Mass Spectrometer</a> (MS) is a magnetic sector analyzer which offers unrivalled precision and accuracy compared with other mass spectrometers. Thermo Fisher Scientific manufactures both quadrupole and magnetic sector mass spectrometers; over thirty years of industrial experience have shown the magnetic sector based analyzer offers the best performance for industrial on-line gas analysis.&nbsp;Key advantages of magnetic sector analyzers include improved precision, accuracy, long intervals between calibrations, and resistance to contamination. Typically, analytical precision is between 2 and 10 times better than a quadrupole analyzer, depending on the gases analyzed and complexity of the mixture.&nbsp;A unique feature of the Prima PRO magnet is that it is laminated. Its analysis times are similar to a quadrupole analyzer, offering the unique combination of rapid analysis and high stability. This allows the rapid and extremely stable analysis of an unlimited number of user-defined gases. The scanning magnetic sector is controlled with 24-bit precision using a magnetic flux measuring device for extremely stable mass alignment.&nbsp;The ion source is an enclosed type for high sensitivity, minimum background interference, and maximum contamination resistance. This is a high-energy (1000 eV) analyzer that offers extremely rugged performance in the presence of gases and vapors that have the potential for contaminating the analyzer. Typical performance specifications for the Prima PRO MS are shown in Table 1. Analytical performance is demonstrated by analyzing the calibration bottle over 1 hour following calibration, with an analysis time of just 6 seconds. Standard deviations measured on the calibration cylinder will be equal to or better than the stated values.

News from LabRulezGCMS Library - Week 07, 2026

Although modern agriculture needs to be based on accurate real-time data on soil, plant, and environmental conditions, affordable, sufficiently sensitive, and robust monitoring devices for this purpose are currently missing. According to scientists, low-cost sensors based on new smart materials and printing technologies offer a suitable solution. The results of multidisciplinary research thus far and proposals for the development of these devices have been presented by researchers from Czechia, Great Britain, Spain, and the USA in a review article in the prestigious journal <a target="_blank" rel="noopener noreferrer" href="https://www.nature.com/articles/s41467-026-68778-6#Abs1">Nature Communications</a>.“Sensor technologies for monitoring plant health are still in their infancy. Only simple sensors capable of monitoring basic parameters such as pH, soil moisture, or temperature are commonly available on the market. However, if farmers are to face current challenges, including climate change, and ensure sufficient food for humanity, they need much more effective tools that will enable them to monitor, for example, various pathogens, including bacteria and fungi. In our opinion, a suitable solution is a combination of new smart materials and printing for the production of inexpensive, durable, and scalable materials,” said the article’s first author, David Panáček from CATRIN, who worked on the study during his internship at Imperial College London.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/CATRIN_Soucasne_senzory_nestaci_Vedci_navrhuji_novou_cestu_ke_sledovani_zdravi_rostlin_b4014952a3.jpg" alt="CATRIN: David Panáček" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_CATRIN_Soucasne_senzory_nestaci_Vedci_navrhuji_novou_cestu_ke_sledovani_zdravi_rostlin_b4014952a3.jpg 208w," sizes="100vw" width="1536" height="1152">Sensors for monitoring plant health, for example, lag behind similar devices used in human medicine. According to the authors, advances in materials science, which will enable the development of scalable sensor technologies, play a key role in this potential shift. “Printing techniques, including inkjet printing, screen printing, aerosol printing, 3D printing, and direct laser writing, offer flexible ways to produce flexible sensors, large-area sensors, and sensors integrated directly into plants. The review article summarizes recent advances in printable low-dimensional materials for agricultural sensors, analyzes their physico-chemical properties in relation to sensor performance, and discusses key challenges and future opportunities requiring interdisciplinary integration,” said one of the corresponding authors, Michal Otyepka.The research brought together materials scientists, chemists, biologists, sensing experts, and printing technology specialists. Materials research and the use of graphene-based smart materials were led by scientists from CATRIN at Palacký University and VŠB-Technical University of Ostrava. Plant biologists from CATRIN contributed their knowledge of plant development, their responses to stress conditions, and the monitoring of their properties. Researchers from Imperial College London took care of the electronics, while representatives from<a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/companies/36"> CEITEC – VUT</a> focused on printing technologies. The team also included leading experts in sensing from the Catalan Institute of Nanoscience and Nanotechnology in Barcelona, and Joseph Wang of the University of California San Diego, the “father of sensing and electrochemistry,” also contributed his extensive knowledge.“This is a groundbreaking study on this topic, which has managed to attract some truly big names in their respective fields. Last but not least, the study demonstrates that interdisciplinarity at CATRIN gives rise to completely new and promising research topics, such as plant sensing and its use for studying plant-environment interactions and smart agriculture,” added another corresponding author, Nuria De Diego.

Current sensors are not good enough. Scientists propose a new way to monitor plant health

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The Multidimensional Chromatography (MDC) Workshop draws experts in this exciting field to share and discuss their research.

The Multidimensional Chromatography Workshop

The Czech Advanced Technology and Research Institute (CATRIN) at Palacký University is a cutting-edge scientific hub dedicated to advancing research in the fields of nanotechnology, biotechnology, and biomedicine. At its core, CATRIN boasts outstanding scientific teams, featuring international researchers. We emphasize interdisciplinarity, foster global collaborations, and work to translate our research findings into practical applications.

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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 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.

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