Determination of residues of tetracyclines in muscle, milk, eggs and honey by HPLC.

N. MIGDAL DI BENEDETTO; MARIELA CHERTOFF; ALBERTO LONGHI

BELGICA

Simposio; Proceeding of Third International Symposium on hormone and veterinary drugs residues analysis; 1998

A method was adapted for simultaneous determination of oxytetracycline (OTC), tetracycline (TC) and chlortetracycline (CTC) residues in muscle, milk, egg and honey by HPLC. The tetracyclines (TCs) were extracted with a metal chelate affinity chromatography and purified using C18 cartridges. The TCs were quantified by reversephase-high-performance- Iiquid-chromatography at 375 nm using a Cs column. The method has been validated for the three TCs. Calibration curves within 50-400 ppbshowed good linear correlation. The mean recoveries at 100 ng/g level were 78% for OTC, 95% for TC and 104% for TC in bovine muscle. The detection limits of the assay for the same matrix were 10,3 ng/g for OTC, 8,4 ng/g for TC and 13,8 ng/g for CTC.The mean recoveries for milk samples fortified with 100 ng/ml were 102% for OTC, 99% for TC and 96% for CTC and the detection Iimits were 21,4 ng/ml for OTC, 24,4 ng/ml for TC and 8,1 ng/ml for CTC. For egg samples fortified at 200 ng/g the mean recoveries were 53% for OTC, 50% for TC and 50% for CTC and the detection limits were 33,4 ng/g for OTC, 33,1 ng/g for TC and 18,5 ng/g for CTC. For honey samples fortified at 100 ng/g the mean recoveries were 97% for OTC, 104% for TC and 103% for CTC and the detection limits of the assay were 16,2 ng/g for OTC, 15,4 ng/g for TC and 7,6 ng/g for CTC. The advantage of the proposed method is the possibility of analyzing different matrix with the same method with a high performance.