17th MDCW 2026 (Day 3)

Program

• Guidebook (PDF)
• Abstract Book (PDF)

Thursday January 15, 2026

8:30 – 8:45 AM Registration

8:45 – 9:00 AM Opening Remarks

9:00 – 9:20 AM O-16 No more split ends? Flow-modulated GC×GC-QMS analysis without splitting off the GC flow

• Kirk Jensen (JEOL USA, Inc.)

Flow-modulated two-dimensional gas chromatography (GCxGC) is an excellent solution for low-boiling point compounds that are difficult to separate by thermal modulation without cryogens. Pairing a quadrupole mass spectrometer (QMS) with GCxGC can offer better dynamic range, increased sensitivity, and lower cost to GCxGC applications, however, many MS instruments can not accept the high flow rate coming from flow-modulated GCxGC. In this study, a flow modulator was installed in a QMS system designed to accept high GC flow rates, and tested using perfume and pesticide applications. Results detailing the sensitivity and effectiveness of the QMS system with high GCxGC flow input will be discussed, as well as a comparison to thermal modulation results from the same system.

MDCW: 17th MDCW 2026 (Day 3): O-16 No more split ends? Flow-modulated GC×GC-QMS analysis without splitting off the GC flow (Kirk Jensen, JEOL USA, Inc.)

9:20 – 9:40 AM O-17 One-shot tensor decomposition of full-scale GC×GC datasets for resolving petrochemical groups

• Paul-Albert Schneide (University of Copenhagen)

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-ofinterest (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, templatebased 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).

MDCW: 17th MDCW 2026 (Day 3): O-17 One-shot tensor decomposition of full-scale GC×GC datasets for resolving petrochemical groups (Paul-Albert Schneide, University of Copenhagen)

9:40 – 10:00 AM O-26 Counting Double Bonds: GC×GC–FID for Plastic Pyrolysis Oils

• Petr Vozka (California State University LA)

Plastic pyrolysis oils (PPOs) are unresolved complex mixtures in which the level and speciation of unsaturation govern storage stability, upgrading severity, and the quality of fuel‑range cuts. Yet routine, transferable olefin quantitation is hampered by extensive coelution and isomer diversity. This talk presents a GC×GC–FID workflow that “counts double bonds” by selectively derivatizing olefins to reposition them within the two‑dimensional separation space, cleanly separating them from paraffins, naphthenes, and aromatics. The method produces carbon-number- and class-resolved olefin distributions (wt.%) for whole oils and distillates in the gasoline, jet, and diesel distillation range.

MDCW: 17th MDCW 2026 (Day 3): O-26 Counting Double Bonds: GC×GC–FID for Plastic Pyrolysis Oils (Petr Vozka, California State University LA)

10:20 – 10:50 AM Coffee Break

11:10 – 11:30 AM O-25 Unexpected solvent selectivity effects in 2D-LC separations of non-ionic copolymer surfactants

• Ella Sontowski (Gustavus Adolphus College)

Analysis of non-ionic copolymer surfactants is challenging due to complexities of the mixture of molecules that results from industrial-scale synthesis involving heterogeneous starting materials. Two-dimensional liquid chromatography (2D-LC) involving hydrophilic interaction (HILIC) and reversed-phase (RP) separation modes has been shown to be particularly effective for this purpose. The HILIC mode is highly selective for the separation of oligomers that vary in the number of hydrophilic (e.g., ethylene oxide [EO]) repeating units, and the RP mode is highly selective for the number of hydrophophic repeating units, such as polypropylene oxide (PO). In our work on separation of EO/PO copolymer mixtures by 2D-LC we have discovered that certain mobile phase compositions used for the HILIC separation yield unexpected selectivities for isomers of these copolymers that can result from differences in the way the EO/PO oligomers are assembled during the synthesis reaction. In this presentation we will share results of a systematic study of mobile phase constituents that exhibit these selectivity effects, and demonstrate the utility of these new-found effects in ultra-high resolution 2D-LC separations of EO/PO copolymers showing that they provide insights into the species-level composition of these complex mixtures that was not possible previously.

11:30 – 11:50 PM O-24 USING SCANNING ELECTRON MICROSCOPY WITH ENERGY DISPERSIVE X-RAY SPECTROSCOPY AND COMPREHENSIVE TWO-DIMENSIONAL GAS CHROMATOGRAPHY TO DEVELOP A COMBINED APPROACH TO GREEN GUNSHOT RESIDUE ANALYSIS IN THE FORENSIC LABORATORY 

• Grace Saunders (William & Mary)

Gunshot residue (GSR) is expelled as a "plume" of vaporized material during a firearm discharge event. As it disperses, condenses, and settles on surfaces in vicinity of the discharge, it creates chemical depositions that provide essential information for forensic casework involving criminal firearm usage. GSR contains organic (OGSR) and inorganic (IGSR) components, both of which may carry evidentiary value. Traditional analyses involve the targeted point analysis of IGSR via scanning electron microscopy - energy dispersive x-ray spectroscopy (SEM-EDS), and conclusions are drawn based on a well-established elemental and morphological profile "characteristic" to IGSR. This method has lost impact as a standard for forensic analysis due to increased use of "green" - heavy metal-free - ammunition, which omits the lead, barium, and antimony that are traditionally seen as the "characteristic" markers of GSR. This study aimed to develop a holistic approach to the analysis of GSR using both SEM-EDS as a targeted approach to IGSR analysis and comprehensive two-dimensional gas chromatography – time-of-flight mass spectrometry (GC×GC-TOFMS) as a nontargeted approach to OGSR analysis. GSR samples were collected from the hands of shooters at a police firearms recertification training using the tape lift method. SEM-EDS was used to identify IGSR and develop new morphological and elemental profiles for heavy metal-free residues. OGSR components have been positively identified through sample analysis via liquid extraction, chromatographic separation via GC×GC-TOFMS, and data processing. Future work on this project will include the optimization of data processing methods and the development of SPME as an alternative sample extraction method.

MDCW: 17th MDCW 2026 (Day 3): O-24 USING SCANNING ELECTRON MICROSCOPY WITH ENERGY DISPERSIVE X-RAY SPECTROSCOPY AND COMPREHENSIVE TWO-DIMENSIONAL GAS CHROMATOGRAPHY TO DEVELOP A COMBINED APPROACH TO GREEN GUNSHOT RESIDUE ANALYSIS IN THE FORENSIC LABORATORY (Grace Saunders, William & Mary)

11:50 – 12:10 PM O-23 Identifying the transition from ante-mortem to post-mortem odor in cadavers in an outdoor environment

• Darshil Patel (University of North Dakota)

This study investigates the transition from ante-mortem to post-mortem odor in human remains during the early post-mortem period in an outdoor environment. Three cadavers (donors) were placed at an outdoor human decomposition facility, and volatile organic compounds (VOCs) were collected and analyzed using thermal desorption coupled with comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (TDGC × GC-TOFMS). The key findings revealed that nitrogen-containing compounds were predominant in early post-mortem VOC profiles, driven by enzymatic and bacterial activity. Esters, alcohols, and halogenated compounds were also identified, with esters linked to microbial transformation and alcohols possibly formed by lipid peroxidation. Ante-mortem VOCs were persistent across samples, influenced by skin microbiota and environmental factors like UV radiation, complicating the detection of decomposition odor. Post-mortem VOCs became more prominent after ADD 73.4(experimental day 3), signaling the transition to the bloat stage of decomposition. Variations in sample collection methods and external factors such as temperature were found to affect VOC abundances. This study provides critical insights into odor transition and has implications for the use of search and rescue (SAR) and human remains detection (HRD) dogs. Further research is needed to standardize methods and assess odor transitions across diverse environments and seasons.

MDCW: 17th MDCW 2026 (Day 3): O-23 Identifying the transition from ante-mortem to post-mortem odor in cadavers in an outdoor environment (Darshil Patel, University of North Dakota)

12:10 – 12:30 PM Poster Awards (Sponsored by SCSC) and Closing Remarks

MDCW: 17th MDCW 2026 (Day 3): GC Poster Prize - Madison L. Williams (The State University at Buffalo New York), Comparison of solid phase microextraction coatings for headspace extraction of volatile perfluoroalkyl substances using one- and two-dimensional gas chromatography

MDCW: 17th MDCW 2026 (Day 3): GC Poster Prize - Madison L. Williams (The State University at Buffalo New York), Comparison of solid phase microextraction coatings for headspace extraction of volatile perfluoroalkyl substances using one- and two-dimensional gas chromatography