Evaluation of a fibrous cellulose drying agent in supercritical fluid extraction and pressurized liquid extraction of diverse pesticides.

A fibrous cellulose powder (CF-1) was investigated as a drying agent for supercritical fluid extraction (SFE) and pressurized liquid extraction (PLE), also known as accelerated solvent extraction. Analysis of fifty-eight diverse pesticides was performed using gas chromatography-ion-trap mass spectrometric detection (GC-ITD). Extraction efficiencies were correlated versus pesticide polarity with samples of different water-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 determined. 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 matrix interferants.