Matrix Solid Phase Dispersion Isolation and Liquid Chromatographic Determination of Oxytetracycline in Catfish (Ictalurus punctatus) Muscle Tissue
Abstract A method for Isolation and liquid chromatographic determination of oxytetracycllne In catfish (Ictalurus punctatus) muscle tissue Is presented. Blank control and oxytetracycllne- fortlfied fish muscle tissue samples (0.5 g) were blended with octadecylsilyl (C18, 40 μm, 18% load, endcapped) derlvatized silica packing material (2 g) containing 0.05 g each of oxalic acid and disodlum ethylenedlamlnetetraacetate. A column made from the C18/fish tissue matrix was first washed with hexane (8 mL), following which the oxytetracycllne was eluted with acetonltrile-methanol (1 + 1, v/v) containing 0.06% w/v each of butylated hydroxyanlsole and butylated hydroxytoluene. The eluate contained oxytetracycllne analyte that was free from Interfering compounds when analyzed by liquid chromatography with UV detection (photodlode array set at 365 nm). Standard curves for oxytetracycllne Isolated from fortified samples were linear (0.998 ± 0.002) with an average absolute percentage recovery of 80.9 ± 6.6% for the concentration range (50,100,200, 400, 800, 1600, and 3200 ng/g) examined. The Interassay variability was 11.3 ± 5.2% with an Intra-assay variability of 1.1%.