A GC-MS METHOD FOR THE ANALYSIS OF FECAL AND PLANT STEROLS IN SEDIMENT SAMPLES

We describe here a new procedure for analysing eleven sterols in envir onmental samples using gas chromatography-mass spectrometry (CC-MS). T his consists of complete silylation of the sterols using N-methyl-N-tr imethylsilyltrifluoroactemide (MSTFA) with iodo-trimethylsilane (TMSI) and a base as catalyst. To assess the applicability of the method to environmental samples and to estimate the extraction efficiency we add ed increasing amounts of sterols to the same sediment sample and quant ified them by the internal standard method. We also analyzed, in three replications, a sediment sample from the Adriatic Sea in order to est ablish the precision of the method.