Determination of residual phenothiazines in liver by matrix solid phase dispersion combined with high performance liquid chromatography with fluorescence detection

Abstract

A simple and fast method for the determination of phenothiazines in bovine liver has been developed. The analytes were isolated from other liver components by a matrix solid phase dispersion (MSPD) procedure involving a mixture of C18 and sea sand as dispersants, a preliminary acidic digestion of the matrix and using acetonitrile as extraction solvent. Because of the complexity of the studied matrix, an extra cleanup of the collected extracts on neutral alumina was required before instrumental determination of the target compounds by high performance liquid chromatography with a fluorescence detector (HPLC-F). The optimised procedure, which involved only 0.250 g of freeze dried sample and a total solvent consumption of 11 mL, allowed accurate determination of the test compounds (recoveries 59–84% and RSD lower than 12% at a spiking level of 200 ng=g wet sample), and limits of detection below 100 ng=g (as calculated for real samples) for all test compounds.