Simultaneous determination of trimethoprim, enrofloxacin, and ciprofloxacin in blood serum of poultry

Resumo

A method is proposed for the simultaneous determination of trimethoprim, enrofloxacin, and ciprofloxacin in blood serum of poultry using HPLC. Samples were prepared using protein precipitation. The chromatographic separation of substances was attained on a C18 column using a mixture of a 50 mM acetate buffer solution (pH 3.0) with acetonitrile (86: 14) as a mobile phase. Detection was performed at 278 nm. Linearity was observed in the concentration range 50–5000 ng/mL for trimethoprim and 10–5000 ng/mL for ciprofloxacin and enrofloxacin. Precision was ≤2.1% for enrofloxacin, ≤1.6% for ciprofloxacin, and ≤14% for trimethoprim. Accuracy was ≤10.2% for enrofloxacin, ≤9.9% for ciprofloxacin, and ≤11.9% for trimethoprim. The method was applied to pharmacokinetic studies of complex antibacterial drugs containing trimethoprim and enrofloxacin as active substances.