EVALUATION OF A FIBROUS CELLULOSE DRYING AGENT IN SUPERCRITICAL-FLUIDEXTRACTION AND PRESSURIZED LIQUID EXTRACTION OF DIVERSE PESTICIDES

A fibrous cellulose powder (CF-1) was investigated as a drying agent f or supercritical fluid extraction (SFE) and pressurized liquid extract ion (PLE), also known as accelerated solvent extraction. Analysis of f ifty-eight diverse pesticides was performed using gas chromatography-i on-trap mass spectrometric detection (GC-ITD), Extraction efficiencies were correlated versus pesticide polarity with samples of different w ater-CF-1 ratios, The effect of water was much more pronounced in SFE using CO2 than PLE using acetonitrile. Pesticide recoveries and limits of detection of fortified tomato samples mixed with CF-1 were determi ned. PLE gave recoveries >80% for nearly all pesticides, and SFE gave similar recoveries except for the most polar and non-polar pesticides. SFE typically gave lower detection limits than PLE due to fewer matri x interferants. (C) 1997 Elsevier Science B.V.