[Determination of Quinclorac in Livestock Products by LC-MS/MS]

A liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based method was developed for determining quinclorac in livestock products. Quinclorac was extracted from the samples using a solution of acetone and hydrochloric acid mixed in a 99 : 1 ratio. The crude extract was purified with ethyl acetate under basic conditions, followed by quinclorac extraction with ethyl acetate under acidic conditions and analysis using LC-MS/MS. The average recoveries of quinclorac from five livestock products (n=5) fortified at the maximum residue limits or 0.01 mg/kg ranged from 85.6 to 93.5%, with the precision of repeatability ranging from 1.7 to 6.8%. The quantification limit in this analytical method was 0.01 mg/kg. These results suggest that the developed method is useful for analyzing quinclorac in livestock products.