A Simple Method for the Characteristic Differentiation of Antibiotics by TLC-Bioautography in Graded Concentration of Ammonium Chloride

Abstract

A simple classification method for 24 known antibiotics by TLC-bioautographic procedure was developed. The approach used was to change the Rf values in seven TLC systems with an ammonium chloride solution in a graded concentration range (0.5, 1, 2, 3, 5, 10 and 20%). The antibiotics were divided into four groups (A to D) showing the characteristic behavior of Rf values corresponding to similarities in chemical structure: β-lactam, aminoglycoside, macrolide and tetracycline antibiotics. TLC-bioautography helps to estimate the character of antibiotics and the characteristic change of Rf values may be very useful for classifying unknown residual antibiotics in animal samples as a routine laboratory test.