Direct detection and quantification of XXXX vapour in humid air using selected ion flow tube mass spectrometry supported by gas chromatography/mass spectrometry.

@entity32909 @entity26 @entity1234 @entity3612 @entity15 @entity1865
RATIONALE: It has been proposed that @entity1234 ( @entity1865 ) reflects free @entity26 -radical lipid peroxidation and can be useful as a biomarker to track this process. For the analysis of @entity1865 molecules in humid air by selected ion flow tube mass spectrometry (SIFT- @entity15 ), the rate coefficients and the ion product distributions for the reactions of the SIFT- @entity15 reagent ions with volatile @entity1865 in the presence of water vapour are required. METHODS: The SIFT technique has been used to determine the rate coefficients and ion product distributions for the reactions of @entity32909 , NO(+) and @entity3612 (+   ) with gas-phase @entity1865 . In support of the SIFT- @entity15 analysis of @entity1865 , solid-phase microextraction, SPME, coupled with gas chromatography/mass spectrometry, GC/ @entity15 , has been used to confirm the identification of @entity1865 . RESULTS: The primary product ions have been identified for the reactions of @entity32909 , NO(+) and @entity3612 (+   ) with @entity1865 and the formation of their hydrates formed in humid samples is described. The following combinations of reagent and the analyte ions (given as m/z values) have been adopted for SIFT- @entity15 analyses of @entity1865 in the gas phase: @entity32909 : 109; NO(+): 89, 102; @entity3612 : 72, 90, 108, 126. The detection and quantification of @entity1865 released by a cell culture by SIFT- @entity15 are demonstrated. CONCLUSIONS: This detailed study has provided the kinetics data required for the SIFT- @entity15 analysis of @entity1865 in humid air, including exhaled breath and the headspace of liquid-phase biogenic media. The detection and quantification by SIFT- @entity15 of @entity1865 released by a cell culture are demonstrated. Copyright    2015 John Wiley _ Sons, Ltd.
