Rapid determination of the antiparasitic drugs flubendazole and febantel in feeds by HPLC with ultraviolet detection

Abstract A rapid and very effective analytical procedure for the simultaneous HPLC determination of two anthelmintics, Flubendazole (FLUB) and Febantel (FEBA), in swine and poultry feeds was developed and tested. The ground feed samples were extracted using dimethylformamide. The extracts were directly analyzed, without any purification, on a reversed-phase ODS column (150 mm × 4.6 mm, 5 μm) with acetonitrile–phosphate buffer (pH 3; 0.017 M) as mobile phase. Ultraviolet detection of FLUB and FEBA was carried out at 300 nm. The method was validated for specificity, linearity, accuracy, repeatability, limit of detection and limit of quantification. The limits of detection (LOD) of FLUB and FEBA in feeds, based on a detector signal-to-noise ratio of 3, were 3 mg kg −1 and the lowest levels tested in feeds by this procedure (limit of quantification, LOQ) were 10 mg kg −1 . The mean recovery of FLUB and FEBA from spiked samples, in a concentration range of 10–200 mg kg −1 , was 98% with a CV% of 4% and 99% with a CV% of 2%, respectively.