LAUSR

A collaborative study for validating the determination method of chlorpropham in feeds by LC-MS/MS was conducted in 13 laboratories using 2 kinds of formula feeds, oats, barley, wheat, and corn. The resulting trueness ranged from 75.3 to 87.0%, repeatability and reproducibility in terms of relative standard deviation (RSDr and RSDR) were within 7.3% and 33% respectively, and the HorRat values ranged from 0.39 to 1.5. The limit of detection and limit of quantitation of chlorpropham in feed ware 0.008 mg/kg and 0.003 mg/kg, respectively. This method was thus validated as useful for inspections of chlorpropham in feed.