PubMed · 3747594
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
D Gui, R M Tacchino, T Emanuele. A simple breath pattern simulator.. https://pubmed.ncbi.nlm.nih.gov/3747594/
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
The effect of derivatization with 2-amino-2-methyl-propanol on trans-3-hexadecenoic acid was investigated as part of the identification of the trans-3-hexadecenoic acid in two Nova Scotian seaweeds. After the extraction of the total fatty acids and their methylation, the monoenoic trans fraction was isolated by thin-layer chromatography on silica gels impregnated with silver nitrate. This fraction was first analyzed by gas chromatography and showed the presence of the trans-3-hexadecenoic acid; other fatty acids were not present. The isolated fraction was derivatized with 2-amino-2-methyl-propanol prior to analysis by gas chromatography/mass spectrometry. The chromatogram obtained showed the presence of a positional isomer formed during the derivatization of the trans-3-hexadecenoic acid. The mass spectrum showed a prominent [M+H] and diagnostic ions for the identification of the unknown isomer, corresponding to the 4,4-dimethyloxazoline (DMOX) derivative of a presumed 2-hexadecenoic acid. Definitive confirmation of the ethylenic bond position was obtained by oxidative ozonolysis of the DMOX derivatives of the fatty acids under investigation. Infrared spectroscopy showed that the artifact formed during the DMOX derivatization of trans-3-hexadecenoic acid was the DMOX derivative of cis-2-hexadecenoic acid.
Explore the source record for details and available documents.
Gas chromatography-tandem mass spectrometry (GC-MS-MS) with selected-reaction monitoring was applied to the analysis of urinary metabolites of sulphur mustard, derived from the beta-lyase pathway and from hydrolysis. In the case of beta-lyase metabolites, a limit of detection of 0.1 ng/ml was obtained, compared to 2-5 ng/ml using single stage GC-MS with selected-ion monitoring. GC-MS-MS methodology was less useful when applied to the analysis of thiodiglycol bis(pentafluorobenzoate) using negative-ion chemical ionisation although selected-reaction chromatograms were cleaner than selected-ion chromatograms. The advantage of using GC-MS-MS was demonstrated by the detection of low levels of beta-lyase metabolites in the urine of casualties who had been exposed to sulphur mustard.