Liquid-Chromatographic Determination of Ciprofloxacin in Serum and Urine

We describe the liquid-chromatographic determination of ciprofloxacin in patients ’ serum and urine. Serum samples were prepared by precipitating protein with perchloric acid. Urine samples were diluted 100-fold with mobile phase. The mobile phase, consisting of pH 3 phosphate buffer/acetonitri-le/methanol (81/5/14, by vol), was pumped through a Bon-dapak C18 reversed-phase column at 1.5 mL/min. Fluores-cence of the effluent was monitored, at wavelengths for excitation and emission of 270 and 440 nm, respectively. Standard curves were linearly related to concentration from 0.08 to 10 mg/L for serum, 1 to 20 mg/L for urine. The procedure was evaluated in a clinical setting to determine Its usefulness in studying the pharmacoklnetics of ciprofloxacin in patients with concurrent diseases and receiving multiple drug therapies