Abstract
A method was developed for the simultaneous determination of 3 sulfonylurea herbicides, azimsulfuron, flazasulfuron and halosulfuron-methyl in agricultural products. The herbicides were extracted with acetone, re-extracted with ethyl acetate, and then transferred to 2% dipotassium hydrogenphosphate solution. The herbicides were extracted again into ethyl acetate and cleaned up using Sep-Pak® Plus Alumina N and Bond Elut® SAX cartridge columns. The 3 sulfonylurea herbicides were determined by HPLC. The fortified peaks were confirmed by LC/MS with electrospray ionization (ESI), and the peaks of azimsulfuron, flazasulfuron and halosulfuron-methyl were determined. The recoveries of the 3 sulfonylurea herbicides from brown rice, corn, cotton seed, ginkgonut, chestnut, almond, walnut, cucumber, pumpkin, orange, grapefruit, mandarin, lemon and grape ranged from 77.0 to 112.3% following fortification at 0.05-0.5 μg/g. The detection limits were 0.01 μg/g for azimsulfuron and halosulfuron-methyl, and 0.02 μg/ml for flazasulfuron(S/N > 3).
