ABSTRACT
A novel method for simultaneous determination of 8 sulfonamide residues (sulfathiazole, sulfapyridine, sulfadiazine, sulfamerazine, sulfamonome-thoxine, sulfachloropyridazine, sulfamethoxazole, and sulfadimethoxine) in honey samples by high-performance liquid chromatography (HPLC) has been developed on the basis of precolumn derivatization with 9-fluorenylmethyl-chloroformate (FMOC-Cl). Sulfonamide residues in honey samples were extracted and purified by matrix solid-phase dispersion with C18 as the solid support. The residues were derivatized by FMOC-CI, and the FMOC-sulfonamide derivatives were further purified by solid-phase extraction with silica gel as the solid support prior to HPLC analysis. The average recoveries for most sulfonamide compounds at different spiking levels (from 10 to 250 microg/kg) were > 70% with relative standard deviations < 16%, and their limits of detection were 4.0 microg/kg. The established analytical method has high sensitivity and repeatability and can be applicable for determining the sulfonamide residues in various honey matrixes.
Subject(s)
Chromatography, High Pressure Liquid/methods , Drug Residues/analysis , Honey/analysis , Sulfonamides/analysisABSTRACT
A novel approach for simultaneous determination of 12 sulphonamides (sulphadiazine, sulphamethazine, sulphathiazole, sulphadimethoxine, sulphamerazine, sulphapyridine, sulphamethoxazole, suphamethizole, sulphaquinoxaline, sulphameter, sulphamonomethoxine, and sulphachloropyridazine) in animal tissues (swine muscle and liver, chicken muscle, beef muscle) by HPLC with UV detection has been developed. A pre-column derivatization of the sulphonamide compounds with 9-fluorenylmethyl chloroformate (FMOC-Cl) has been proposed and the reaction conditions have been optimized. The FMOC-sulphonamide derivatives were purified by SPE with silica gel as solid support prior to HPLC separation. The limits of detection for the sulphonamide compounds were greatly improved after the derivatization and purification step for the derivatives. Sulphonamide residues in animal tissues were extracted by acetonitrile and purified by solid phase extraction with C(18) as the solid support. The method developed has high sensitivity and good repeatability, and the average recoveries for most of the sulphonamides at various spiking levels were above 70% with relative standard deviations below 13.7%. The limits of detection for most sulphonamides can reach 3-5 microg/kg.
Subject(s)
Chromatography, High Pressure Liquid/methods , Drug Residues/analysis , Fluorenes/chemistry , Sulfonamides/analysis , Animals , Hydrogen-Ion Concentration , Kinetics , Sensitivity and Specificity , Spectrophotometry, Ultraviolet , TemperatureABSTRACT
A novel approach for determination of 2-mercaptobenzimidazole (MBI) and other thyreostatic residues in animal tissues by gas chromatography/mass spectrometry (GC/MS) in selected ion monitoring mode was developed. The analytes in animal tissues (including hypothyroid, pork muscle and beef samples) were extracted by acetonitrile, and then purified by a matrix solid-phase dispersion (MSPD) procedure after the extraction residues had been dissolved in water. The thyreostatic residues were derivatized by pentafluorobenzyl bromide (PFBBr) under strong basic conditions and then N-methyl-N-(trimethylsilyl)trifluoroacetamide (MSTFA) before GC/MS analysis. Different kinds of solid supports with various polarities for the MSPD procedure were investigated, and it was found that silica gel was suitable for the purpose. The average recoveries of the thyreostatic drugs in animal tissues ranged from 71.5-96.9% with the relative standard deviations below 10%. By using the developed method, the limits of detection were 10 microg/kg for MBI; 5 microg/kg for 6-phenyl-2-thiouracil; and 2 microg/kg for 2-thiouracil, 6-methyl-2-thiouracil and 6-propyl-2-thiouracil. The stability of the thyreostatic drugs in spiked animal tissues was tested, and the results showed that the thyreostatic drugs did not decompose within 3 months if the sample was stored in darkness below -20 degrees C.
