[Determination of imidocarb residue in swine tissues by high performance liquid chromatography]

A quantitive method for the determination of imidocarb residue in edible tissues of swine by high performance liquid chromatography (HPLC) was developed. The analyte was digested by beta-glucosidase first, and then extracted with 1 mol/L hydrochloric acid. The aqueous phase was back-extracted with the mixture of hexane-isoamyl alcohol (3: 2, v/v) for the purification. The mobile phases were acetonitrile (phase A) and 0.007 5 mol/L 1-pentansulfonic acid sodium aqueous solution containing 0.1% triethylamine, adjusted to pH 3.0 with glacial acetic acid (phase B). The analyte was detected by ultraviolet absorption spectroscopy after the separation was achieved on a C18 RP column. The linear range was 10 - 10 000 micog/L, and the correlation coefficient was more than 0.999. The limit of detection (LOD) was 10 microg/kg, and the limit of qualification (LOQ) was 20 microg/kg. The mean recoveries of imidocarb in swine tissues at the added levels of LOQ, MRL (maximum residue limit) and 2MRL ranged from 80.04% to 110.32%, and the relative standard deviations (RSDs) of intra- and inter-day analyses ranged from 0.82% to 10.00%. The method is simple and sensitive for the quantification of imidocarb residue in swine tissues.