Pyrolysis Gas Chromatography Mass Spectrometry Assessment of Low-Concentration Sarcosine in Water Based Samples

In this study, Curie point flash pyrolysis gas chromatography mass spectrometry (Py-GC-MS) method was applied for detection of sarcosine in water based samples. Among the variety of sarcosine pyrolysates−two distinguished thermal decomposition compounds were detected with clear chemical pathways (dimethylformamide, DMA, and dimethylacetamide, DMA). The amount of both pyrolysates showed the increase proportional to the initial sarcosine concentration in aqueous samples, and this fact was used for the original compound detection and quantification. Novel and simple sample preparation was applied satisfying the “green chemistry” requirements consisting of drying of aqueous sample in pure helium to remove water. Py-GC-MS analytical method was optimized for the following parameters: volume of the sample and pyrolysis temperature. Matrix influence tests with other amino acids (methionine, L-alanine, L-cysteine, L-valine, L-leucine, L-threonine, L-lysine, glycine, and L-histidine) and urea were conducted and confirmed the applicability of method for selective detection of sarcosine based on the amount of its pyrolysates DMF and DMA.