TMIC’s Node publication by Dr. James Harynuk Node at TMIC “Evaluation of fresh, frozen and lyophilized fecal samples by SPME and derivatization methods using GCxGC-TOFMS” highlights the benefits of using multidimensional gas chromatography in the studies of complex samples. Dr. Harynuk lab at University of Alberta utilizes a powerful separation analytical platform – two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GCxGC-TOFMS). This technology offers superior analytical performance, including enhanced sensitivity and dynamic range compared to one-dimensional GC, and is well suited for analysis of complex mixtures such as feces. The studies with this technique can be performed at Dr. Harynuk’s lab – contact us for details.
Untargeted Metabolomics by GCxGC TOF MS is a semi-quantitative method for known and unknown metabolite profiling. It is an ideal discovery platform for analysis of volatile and semi-volatile compounds, as well as compounds that can be derivatized with standard chemistries, allowing us to also detect simple sugars, sterols and larger molecules. Aside from simple liquid injections of extracts, a wide range of injection methods are available including solid-phase microextraction, static headspace, dynamic headspace, and thermal desorption. This allows us to easily handle a wide variety of sample types including soil, water, oil/petroleum, air samples, plants, food and beverages, breath, and biofluids (ie. urine, plasma, etc). This service typically allows for the detection of 2000-9000 features (sample dependent). Relative quantification is provided based on peak areas, normalized to appropriate internal standards.
- Objective: The effects of sample handling conditions on fecal metabolite profiles and abundances were examined using comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry
- Methods: Solid-phase microextraction (SPME) and derivatization via trimethylsilylation (TMS) were employed to evaluate samples.
- Results: The metabolic profiles of fecal samples depend greatly on the sample handling and processing conditions.
- Conclusions: Based on the authors’ results, snap-freezing at -80 0C would be preferred over lyophilization for handling samples.
This study was performed by Dr. Harynuk Node in collaboration with DNA Genotek (ON, Canada) researchers.