Determination of 13C-enrichment in bacterial fatty acids using chemical ionization mass spectrometry with negative ion detection
Saturated, monoenoic and β-hydroxysubstituted fatty acids, 13C-labelled at the carboxyl group, were prepared from natural or synthetic unlabelled analogues. The synthetic route involves decarboxylation of the unlabelled fatty acid to the next lower iodide, displacement of iodide for [13C]cyanide and hydrolysis. The fatty acids were converted to their pentafluorobenzyl esters and analysed by select
