Fluorometric Determination of Tetracyclines in Honey by High Performance Liquid Chromatography

• Published in: Food Hygiene and Safety Science (Shokuhin Eiseigaku Zasshi) Vol. 32; no. 1; pp. 43 - 47_1
• Main Authors: KOBAYASHI, Yoshio, NAKAYA, Ken-ichi, TANAHASHI, Nobuyasu
• Format: Journal Article
• Language: English; Japanese
• Published: Japanese Society for Food Hygiene and Safety 1991
• Subjects: chlortetracycline; high performance liquid chromatography (FL); honey; oxytetracycline
• ISSN: 0015-6426; 1882-1006
• DOI: 10.3358/shokueishi.32.43

A sensitive and selective method for determination of oxytetracycline (OTC) and chlortetracycline (CTC) in honey by high performance liquid chromatography with a fluorescence detector was developed. A honey sample was dissolved in 0.1N hydrochloric acid and passed through a Sep-Pak C18 cartridge. After washing of the cartridge with water, OTC and CTC were eluted with methanol and purified by counter-ion extraction. The isolated OTC was treated with magnesium acetate-sodium barbital solution and CTC was treated with 0.05M KOH to obtain a fluorescent derivative. OTC and CTC were separated on an Asahipak Gel ODP-50 column and quantitated by fluorometry. The mobile phase for OTC was 0.1M glycine buffer (pH 10)-methanol (20:1) containing 20mM sodium 1-heptane-sulfonate (final concentration) and that for CTC was 0.01M glycine buffer (pH 10)-methanol (5:1). The recoveries of OTC and CTC added to honey at levels of 0.5ppm and 1ppm were 68.5 and 73.2% for OTC, and 53.1 and 68.1% for CTC, respectively. The limits of detection were 0.02ppm for OTC and 0.005ppm for CTC.