An Organic Solvent-free and Simple Procedure for Quantifying Tetracycline and 4-epi-tetracycline in Milk

From the perspective of ensuring food safety, this chapter introduces a new quantification method for effective a veterinary drug (particularly frequently used) that lead to enhanced food residue monitoring. Under organic solvent-free conditions, a quick, easy, small-scale sample preparation followed by an isocratic mobile phase HPLC for quantifying tetracycline (TC) and its 4-epimer, 4-epi-tetracycline (4eTC), in cow’s milk was described in this paper. The sample preparation could be made only homogenization using a handheld ultrasonic-homogenizer with deproteinizing aqueous solution followed by filtration with disposable unit. For determination and identification of analyte, an Inertsil WP300 C4 and isocratic 100% aqueous mobile with photodiode array detector was used. The method validation data were well within the international analytical method acceptance criteria. The total time required for the analysis of one sample was less than 7 min. In all the process, no organic solvents were used. The present method may be proposed as an international harmonized analytical method for routine residue monitoring of TC and 4eTC in cow’s milk.