MOBILITY OF AVERMECTIN B-1A IN SOIL

Avermectin Bla(AVM) was determined to be immobile in soil by three methods: sorption/desorption using a batch equilibrium technique, soil thin-layer chromatography, and soil column leaching using aged and unaged soil. From the sorption data from batch equilibrations of AVM with three soils, the Koc(distribution constant normalized to the percent organic matter) for AVM was determined to be 4.76 X 103. When ascending chromatography was performed on TLC plates prepared with six different soils, average Rfvalues for AVM and 2,4-dichlorophenoxyacetic acid, a pesticide of known mobility, were determined to be 0.00 and 0.78, respectively. Also, AVM did not readily leach from four soils in soil column leaching studies. © 1990, American Chemical Society. All rights reserved.