Determination of Organophosphate Pesticide Residues in Rice by Multiresidue Analysis
CHIEN CHU*, SUE-SUN WONG AND GWO-CHEN LI
Taiwan Agricultural Chemicals and Toxic Substances Research Institute, Council of Agriculture, 11 Kuang-Ming Rd., Wufeng, Taichung Hsien, Taiwan, R.O.C.
ABSTRACT
An analytical method was developed for determination of 47 organophosphate pesticides in rice by using solid-phase extraction for clean up. Pesticides in rice samples were extracted with acetone. The extract was cleaned up with 1 g C18 solid-phase extraction (SPE) cartridges and the pesticides were determined using a gas chromatography-flame photometric detector (GC-FPD).The recoveries of 47 pesticides ranged from 74%-126% and the detection limits were 0.005 - 0.04 μg/g. Several pre-treatment methods are compared for the simultaneous analysis of organophosphorus pesticides in rice. Cleanup with SPE showed results comparable to or better than those obtained by liquid-liquid extraction. The SPE method enhances the effect and reduces analytical cost and time.
Key words: rice, organophosphorus pesticides, residues, solid phase extraction.