Determination of Veterinary Pharmaceuticals in Production Wastewater by TLC-densitometry

Abstract

SPE-HPTLC method for simultaneous identification and quantifica tion of three pharmaceuticals in production wastewater was optimized and validated. The studied compounds were oxytetracycline, trimethoprim and sulfamethoxazole. The method involves solid-phase extraction on hydrophilic-lipophilicbalance cartridges with methanol followed by TLC-densitometricanalysis of extracts on chromatographic plates at 254 nm. Optimization of chromatographic separation was performed by systematic variation of the mobile phase composition using genetic algorithm approach and the optimum mobile phase composition for TLC separation was Toluene, ethyl acetate, and methanol (50, 28.5, 21.5, v/v/v). Linearity of the method was demonstrated in the ranges from 0.15-1.25 μg/band for oxytetracycline, 0.15-0.5 μg/band for trimethoprim, 0.05-0.5 μg/band for sulfamethoxazole. Mean recoveries percentage ranged from 73.9 to 105.2 % for a production wastewater, respectively. The described method has been applied to the determination of pharmaceuticals in wastewater samples from pharmaceutical industry.