Improvement of chemical analysis of antibiotics. XIII. Systematic simultaneous analysis of residual tetracyclines in animal tissues using thin-layer and high-performance liquid chromatography.

A simultaneous analytical system for residual tetracycline antibiotics (TCs) in animal tissues including liver has been developed. This system consists of three methods using Baker 10 C18 clean-up followed by high-performance liquid chromatography (method A), thin-layer chromatography (TLC)-UV densitometry (method B) and TLC with spray reagents (method C). Methods A and B were established for the precise determination of TCs and method C for universal screening. The recoveries from beef liver fortified at the level of 1.0 ppm and their coefficients of variation were 60.5-83.3% and 2.3-3.9% (method A) and 58.1-92.8% and 1.0-3.7% (method B), respectively. The detection limits in animal tissues were 0.01 ppm (method A) and 0.1 ppm (methods B and C). The time required for the analysis of four samples was 2.5-3 h with each method.