[Detection of antibiotics in biological materials for purposes of toxicological analysis. I. Methodologic study for the detection of tetracycline].

A method of the identification of tetracycline antibiotics in urine and gastric content, suitable for the routine toxicological analysis, was worked out. For the isolation, the extraction with ethyl acetate is recommended. The TLC method on Silufol layers impregnated with an aqueous solution of the disodium salt of ethylenediaminetetraacetic acid (Na2EDTA), in the concentration of 0.1 mol/l and pH value of 5 or 7.4 is used for the identification. The mobile phase chloroform--methanol--Na2EDTA 55:30:5 is suitable for the development of these layers; UV light of the wavelength 254 or 366 nm and Fast Blue B reagent are used for the detection. The conditions of the TLC (various modifications of the layer, mobile phase and detection) and the extraction solvents suitable for the isolation are discussed.