Abstract
Simultaneous determination of various kinds of pesticides (carbamate, urea and acid-amide derivatives) was described. The pesticides were extracted from sample with acetonitrile or acetone, diluted with 10% NaCl solution, and re-extracted with dichloromethane. The organic layer was concentrated, purified with Sep-pak Florisil[○!R], derivatized to the corresponding methyl or trifluoroacetyl derivatives, and then determined by gas chromatograph with a flame thermionic or electron capture detector. Recoveries of 12 pesticides (swep, chloropropham, diuron, linuron, propanil, propyzamide, propoxur, isoprocarb, BPMC : o-sec-butylphenyl methylcarbamate, XMC : 3, 5-xylyl methylcarbamate, MTMC : m-tolyl methylcarbamate, MPMC : 3, 4-xylyl methylcarbamate) added to orange and unpolished-rice at 0.1 ppm, were within the range of 90.5-95.1%.
