SIMULTANEOUS SEPARATION AND QUANTITATIVE DETERMINATION OF TETRACYCLINE ANHYDROTETRACYCLINE 4-EPTETRACYCLINE AND 4-EPI-ANHYDROTETRACYCLINE IN DEGRADED TETRACYCLINES BY THIN-LAYER CHROMATOGRAPHY

A rapid procedure is described which permits the quantitative separation and determination of tetracycline (TC), 4‐epitetracycline (ETC), anhydrotetracycline (ATC), and 4‐epi‐anhydrotetracycline (EATC) on the same plate by thin‐layer chromatography, on kieselguhr impregnated with EDTA at pH 7.5 with ethyl acetate‐acetone‐water (10:20:3) as solvent, or on kieselguhr with EDTA at pH 9 and water‐acetone (1 :10) as solvent. The method has an incalculable value in the diagnosis of degraded tetracyclines, it permits the determination of 0.5% of each one of the above‐mentioned products in the presence of tetracycline, and it detects quantities of about 0.1% in degraded tetracyclines. Copyright © 1969 Wiley‐Liss, Inc., A Wiley Company