Simultaneous determination of 7 kinds of pyrethroids in agricultural products by capillary ECD-GC.

Abstract

Simultaneous determination method of 7 kinds of pyrethroids (pyrethrum, permethrin, cypermethrin, flucythrinate, fenvalerate, fluvalinate and tralomethrin) was investigated. Two to twenty g of minced fruits, vegetables or potatoes were homogenized with acetone, filtered, and concentrated to 50 ml. Then, 50 ml of coagulating reagent and 5 g of Celite 545 was added and filtrated by sunction. Green tea leaves were infused with boiling water. Tannic acid in the green tea extract was removed by the saturated lead acetate solution. Then, 100 ml of 10% NaCl was added and pesticides was extracted twice by 100 ml of n-hexane and concentrated to 5 ml. Lipids were removed by n-hexane-acetonitrile partition and the samples were purified using Florisil column. Pyrethroids were determined by ECD-GC using capillary column CBP1. Recoveries of 7 pyrethroids added at the concentrations of 0.25-4.72 ppm were 67.6-97.3% for vegetables, fruits and potato, 27.4-82.7% for polished rice and soybean, and 31.5-89.3% for green tea extract. But some pyrethroid components of pyrethroids in the peel of natsumikan were unable to determine because of interfering peaks. None of the 7 pyrethroid pesticides was detected by ECD-GC and GC-MS identification.