An Isotope Dilution Mass Spectrometric (IDMS) Method for the Determination of Vitamin C in Milk

Abstract

(HCB) using the 1 C6 -labelled standard [6]. For the analysis of eggs, sample preparation involves initial treatment with phospholipase, extraction with acetone/hexane and then clean-up of the lipid extract on a water deactivated alumina column. Selected ion monitoring is for m/z 284 and 286 for HCB and 292 and 294 for I1 C6 ]HCB. The GC/MS program involves switching between a number of different ions, grouped for different retention time windows to enable monitoring of altogether 10 organochlorine pesticides plus respective isomers. For the future it is intended to increase the number of isotopically labelled standards utilized which will further increase the complexity of the multiple ion monitoring program.