Automated Analysis of Organophosphorus Pesticide Residues in Foods Using Supercritical Fluid Extraction

Abstract

Organophosphorus pesticide residues in foods were extracted by means of supercritical fluid extraction (SFE). The extracted pesticides were determined consecutively by GC-FPD detection under the control of a computer. Samples were mixed with two kinds of drying agents, diatomaceous earth or a super-absorbent polymer, before extraction to remove water. Thirty-three out of 35 pesticides tested were extracted with good recovery and determined with high precision, though acephate and methamidophos were hardly recovered when diatomaceous earth was used and poorly recovered with the super-absorbent polymer. Most interfering substances, such as fats and green food colors, were not extracted during the proposed extraction process. These results suggest that extraction by SFE coupled with selective detection is suitable for the analysis of pesticide residues in foods.