Determination of Tetracycline Antibiotics in Beef and Pork Tissues Using Ion-Paired Liquid Chromatography

• Published in: Journal of agricultural and food chemistry 2000-06, Vol.48 (6), p.2244-2248
• Main Author: Moats, William A
• Format: Article
• Language: English
• Subjects: Animals; Biological and medical sciences; Cattle; Chromatography, High Pressure Liquid - methods; Chromatography, Liquid - methods; Food industries; Fundamental and applied biological sciences. Psychology; General aspects; Indicators and Reagents; Kidney - chemistry; Liver - chemistry; Meat and meat product industries; Methods of analysis, processing and quality control, regulation, standards; Muscle, Skeletal - chemistry; Swine; Tetracyclines - analysis
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf990649r

A simplified procedure was developed for determination of tetracycline antibiotics in tissues which improved stability of these compounds in sample extracts and eliminated the need for troublesome cleanup procedures. Tissues were homogenized in water. Acetonitrile (16 mL) and then 1 mL of 0.1 M H3PO4 were added to 4 mL of homogenate and the clear supernatant was filtered. The filtrate was mixed with hexane and dichloromethane and the resulting water layer was collected, evaporated to 1−2 mL, and filtered into autosampler vials. Ion-pairing liquid chromatography was used to separate tetracyclines from interferences in sample extracts, eliminating the need for further cleanup. Analysis was isocratic using a Phenomonex Prodigy ODS(3) column with a mobile phase of 4 mM oxalic acid, 4 mM sodium oxalate, 10 mM sodium decanesulfonate−acetonitrile (70 + 30 for oxytetracycline and tetracycline; 66 + 34 for chlortetracycline). Recoveries were generally in the 90−100% range with limits of quantitatation of 0.05−0.1 ppm. The procedure was evaluated with beef and pork muscle, liver, and kidney. Keywords: Tetracycline; oxytetracycline; chlortetracycline; beef; pork; tissues; determination; liquid chromatography