High-performance liquid chromatographic determination of imidocarb in cattle kidney with cation-exchange clean-up.

A high-performance liquid chromatographic (HPLC) method for the determination of the antiprotozoal agent imidocarb in cattle kidney is developed. The drug is extracted from tissue with acetone in the presence of base. The extract is partitioned between saturated salt and chloroform and the organic layer evaporated to dryness. Clean-up is by cation-exchange solid-phase extraction on a carboxylic acid column. HPLC analysis is carried out on a Spherisorb S3W-PC18 column with ultraviolet detection at 260 nm. Average recoveries at the 0.05 and 0.01 mg kg-1 levels are 77.5 and 76.3%, respectively. The limit of detection is 0.001 mg kg-1.