Determining Propoxur and Other Carbamates in Meat Using HPLC Fluorescence and Gas Chromatography/Ion Trap Mass Spectrometry after Supercritical Fluid Extraction

Supercritical fluid extraction (SFE) using CO2 was examined for separating carbamate pesticides from interfering coextractives prior to analysis either by liquid chromatography with fluorescence detection or by gas chromatography/ion trap mass spectrometry (GC/ITMS). Pre-extraction of the ground meat with acetonitrile prior to SFE left behind over 99% of the fat and fiber in ground meat. The concentrated acetonitrile extracts containing the carbamates and other coextractives were adsorbed on a pelletized diatomaceous earth for SFE. SFE further reduced the amount of coextractives 10-fold. This procedure allows larger, more representative samples to be routinely analyzed, removes interferences that appear in the fluorescence mode, and reduces many of the non-volatiles that can accumulate on the capillary column in the GC/ITMS mode and shorten its lifetime after multiple injections