James. J. Harynuk

Comprehensive two-dimensional (2D) gas chromatography mass spectrometry (GC×GC-MS) provides improved separation quality in comparison to one-dimensional (1D) GC-MS; however, it presents with undesirable noise akin to that of 1D, including background chemical, thermal, and electrical noise. In GC×GC-MS, the narrow peak widths necessitate the use of a fast detector, often a time-of-flight mass spectrometer (TOFMS), acquiring more than 50 spectra per second (Hz). These high detector speeds increase electrical noise. Using a Fast-Fourier Transform (FFT), it is possible to analyze GC×GC-TOFMS data in the frequency domain, which has not yet been explored and addressed in literature. In doing so, we identified intense bands in the frequency domain of both GC-MS and GC×GC-TOFMS data corresponding to common alternating current (AC) frequencies resulting from electrical components in MS detectors operating at sufficiently high acquisition rates. In GC×GC-TOFMS data, we discovered that the periodic resampling of peaks introduces equispaced bands into the frequency domain that are separated by the frequency of the modulation period. To improve data quality, we developed an algorithm operating in the frequency domain to filter unwanted noise while simultaneously preserving and enhancing chemical features. The algorithm uses Butterworth filtering to notch out AC-associated frequencies, reducing the standard deviation of the baseline noise of the total ion chromatogram (TIC) in both GC-TOFMS and GC×GC-TOFMS by 30-50%. Further, all frequencies above a specified threshold can be removed using a Butterworth lowpass filter, providing additional denoising of frequencies unassociated with chemical features. An exponential fit can also be applied to GC×GC-TOFMS data in the frequency domain, intensifying the low, chemical-associated frequencies and damping higher ones. The latter significantly reduced noise in the time domain and decreased baseline standard deviation by over 25%, albeit at the cost of slightly broadened peaks, thus decreasing resolution. Applying all enhancement methods in superposition recovers peaks along the first-dimension baseline of GC×GC-TOFMS data that were previously obscured by noise. The application of this algorithm allows for the denoising of chromatographic data while preserving and optimizing chemical features.

Standardized quality assurance and quality control (QA/QC) practices are essential for reproducible GC–MS metabolomics, yet systematic documentation of current laboratory practices has been lacking. Here, as part of the Metabolomic Quality Assurance and Quality Control Consortium (mQACC), we surveyed 85 laboratories from 27 countries to characterize QA/QC implementation and establish evidence-based recommendations. Respondents represented diverse applications, with 79% performing untargeted analysis, 60% conducting targeted analyses, and 44% conducting both. While single column chromatography is clearly the norm, 24% of the participants used multidimensional chromatography to improve the separation of complex mixtures. Electron ionization with autotuning dominated >95% of the respondents, but more than 30% of the laboratories at least occasionally also used chemical ionization. While most laboratories used low-resolution mass spectrometers, almost half of the laboratories also performed GC–MS analyses on high-resolution QTOF or Orbitrap instruments. A strong consensus emerged on critical QA/QC practices: >90% of laboratories use internal standards for quality control, perform regular leak checks, and maintain injector systems through routine component replacement, spanning column (exchange/cuts), liners, syringes, and septa. Routine monitoring (>50%) involves method blanks, peak shape assessments, and systematic evaluation of intensity drifts, carryovers, and contamination. Retention indices coupled with mass spectral library matching served as the primary annotation approach (60%). Overall, a consensus of best practices in QA/QC and reporting emerged, providing evidence-based recommendations for high-quality GC–MS metabolomics.

BACKGROUND: In Canada, the orange wheat blossom midge (hereafter called wheat midge), Sitodiplosis mosellana (Géhin) (Diptera: Cecidomyiidae), causes millions of dollars of damage to wheat crops every year. Host plant nutrition directly or indirectly influences insect oviposition owing to their higher food quality. We tested the effect of fertilizer rates (0.5, 1.5, 2.5 g per pot) on plant growth parameters, tissue nitrogen (N) content, protein content, wheat midge oviposition, and larval performance using a susceptible wheat cultivar, ‘Roblin’. We also examined the volatile organic compound (VOC) profile in plants grown under different fertilization regimes using thermal desorption comprehensive 2D gas chromatography time‐of‐flight mass spectrometry (TD‐GC × GC‐TOFMS) to test whether VOCs are influenced by plant fertilization. RESULTS: Higher fertilization rates increased plant fresh weight and number of spikes per plant. However, the highest percentage of nitrogen and protein content were observed in the moderate fertilization treatment, followed by the high and low treatments. Wheat midge laid proportionally more eggs in the moderate than in the high fertilization treatments, with intermediate numbers of eggs observed in the low fertilization treatment, in choice oviposition tests. Fertilizer treatments did not affect the total number of wheat midge eggs and larvae, and the average larval weight in no‐choice tests. The VOC profile of plants in the moderate and high fertilization treatments differed from that of the low fertilization treatment. CONCLUSIONS: Plant fertilization increases plant growth, nitrogen, and protein levels, alters the VOC profile, and affects female wheat midge oviposition preference. Increased egg‐laying may be affected by the observed changes in the VOC profile, which warrants further investigation comparing the effects of fertilization on the VOC profiles of susceptible and oviposition‐deterrent wheat varieties. Under no‐choice conditions we did not detect fertilization effects on wheat midge oviposition or early development, but future studies should focus on potential effects on adults and their reproduction. These findings provide a deeper understanding of how plant nutrients influence wheat midge–host plant interactions. © 2026 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Oxidative stress is a biological imbalance that contributes to cellular damage and is a major driver of aging and age-related disorders, prompting the search for natural antioxidant agents. Our study is a phytochemical, electrochemical, and biological characterization of the antioxidant potential of aqueous extracts from aerial parts of A. occidentale—leaves, bark, fruit, and cashew nuts—traditionally used in folklore medicine. Extracts were analyzed using FT-IR spectroscopy, GC × GC-TOFMS, polyphenol quantification, and antioxidant capacity assays (ABTS, FRAP, DPPH). Biological activity was tested in different mice and human cell lines (SH-SY5Y, MEF, ARPE-19, and HLECs). Aqueous extracts from the leaves and bark of A. occidentale exhibited significantly higher antioxidant activity compared to those from the fruit and cashew nut. These extracts showed elevated polyphenol content and strong performance in antioxidant capacity assays. In vitro, leaf and bark extracts enhanced cell viability under H₂O₂-induced oxidative stress, preserved mitochondrial membrane potential, and upregulated cytoprotective genes (HMOX1, NQO1, GCLC, and GCLM) in multiple cell lines. In contrast, fruit and nut extracts showed minimal antioxidant activity and no significant gene modulation. Our findings underscore the therapeutic potential of A. occidentale leaf and bark extracts as effective natural antioxidants and support their further development as candidates for phytotherapeutic interventions.

Scientific collaboration traditionally relies on activities such as workshops, training programs, services, conferences, and personal meetings. In recent years, commercial-academic partnerships and global events such as pandemics have accelerated the development of online interaction platforms. A key challenge is to create immersive and interactive environments that extend beyond conventional search engines and video conferencing. This article introduces a novel 3D model platform compatible with the Metaverse of Academic Nexus for Global Opportunities (MANGOs), highlighting its potential applications in gas chromatography (GC) and comprehensive two-dimensional gas chromatography (GC×GC). The platform offers participants a virtual ecosystem for exploring fundamental concepts, practicing analytical skills, conducting experimental simulations, and sharing databases. Key features include virtual university settings, buildings, laboratories, instruments, a retention index (I) database, and immersive GC and GC×GC simulation environments for a variety of samples. Simulations of chromatograms and contour plots based on literature-reported experimental conditions are demonstrated. This new approach aims to enhance collaboration among gas chromatographers by enabling skill development, data exchange, and collective refinement of results obtained under diverse experimental setups.

Oxidative stress is a biological imbalance that contributes to cellular damage and is a major driver of aging and age-related disorders, prompting the search for natural antioxidant agents. Our study is a phytochemical, electrochemical and biological characterization of antioxidant potential of aqueous extracts from aerial parts of A. occidentale—leaves, bark, fruit, and cashew nuts- traditionally used in folklore medicine. Extracts were analyzed using FT-IR spectroscopy, GC×GC-TOFMS, polyphenol quantification and antioxidant capacity assays (ABTS, FRAP, DPPH). Biological activity was tested in different mice and human cell lines (SH-SY5Y, MEF, ARPE-19 and HLEC). Aqueous extracts from the leaves and bark of A. occidentale exhibited significantly higher antioxidant activity compared to those from the fruit and cashew nut. These extracts showed elevated polyphenol content and strong performance in antioxidant capacity assays. In vitro, leaf and bark extracts enhanced cell viability under H₂O₂-induced oxidative stress, preserved mitochondrial membrane potential and upregulated cytoprotective genes (HMOX1, NQO1, GCLC, and GCLM) in multiple cell lines. In contrast, fruit and nut extracts showed minimal antioxidant activity and no significant gene modulation. Our findings underscore the therapeutic potential of A. occidentale leaf and bark extracts as effective natural antioxidants and support their further development as candidates for phytotherapeutic interventions.