Multiresidue Determination of Veterinary Drugs in Chicken and Swine Muscles by High Performance Liquid Chromatography
Ya-Min Kao*, Mei-Hua Chang, Chieu-Chen Cheng and Shin-Shou Chou
National Laboratories of Foods and Drugs, Department of Health, Executive Yuan 161-2, Kuen-Yang Street, Nankang, Taipei, 115, Taiwan, R.O.C.
(Received: July 13, 2000; Accepted: September 21, 2000)
ABSTRACT
A high performance liquid chromatographic (HPLC) method equipped with a photodiode array detector was evaluated for the residual determination of 13 veterinary drugs, including clopidol, sulfadiazine, sulfathiazole, carbadox, sulfamerazine, ormethoprim, sulfamethazine, furazolidone, sulfamonomethoxine, sulfamethoxazole, ethopabate, sulfaquinoxaline, and sulfadimethoxine in chicken and swine muscles. Test samples were extracted with acetonitrile and filtered. The filtrate was partitioned with acetonitrile-saturated n-hexane for removing the interference. After evaporation to dryness, the residue was passed through a Sep-Pak C18 cartridge for sample cleanup prior to HPLC analysis. Veterinary drugs were determined by HPLC equipped with a photodiode array detector using a Luna 5 m C18 (2) 25 cm X 4.6 mm i.d., 5 mm) analytical column and a gradient elution of acetonitrile and 0.05M sodium dihydrogen phosphate. The average recoveries of 13 veterinary drugs from chicken and swine muscles at the levels of 0.1, 0.2 and 0.4 ppm were in the range of 71.9 ～96.9% and 71.1~99.6%, respectively, with coefficients of variation less than 8%. The detection limits were 0.04 ppm for sulfathiazole and 0.02 ppm for other 12 drugs.
Twenty-five samples each of chicken and swine muscles collected from local markets in Taipei were investigated for veterinary drug residues. One chicken muscle sample was found to contain 1.23 ppm sulfaquinoxaline, the level of which exceeded the regulated tolerance.
Key words: veterinary drug, multiresidue, photodiode array detector, high performance liquid chromatography