Determination of Ciprofloxacin in Human Serum by Online Heart-Cutting Liquid Chromatography

Abstract

In this study, a very simple, selective and sensitive new online heart-cutting liquid chromatographic method was developed for the determination of ciprofloxacin in human serum. The proposed method allows the determination of ciprofloxacin in human serum without complex sample preparation. The samples were mixed with methanol and filtered before analysis. Separations were performed with the following systems: the first dimension consisted of a biphenyl (50 mm x 2.1 mm) pre-separation column and the mobile phase of 25 % methanol: 75 % 30 mM ortho-phosphoric acid solution mixture, and the second dimension consisted of a C18 (150 mm x 4.6 mm) separating column and the mobile phase of 15 % acetonitrile: 85 % 50 mM ortho-phosphoric acid (pH 3.5, 100 mM triethylamine) solution mixture. The two systems were connected with a six-port valve including a 200-mu L sample loop and separations were performed continuously through injections. Detection wavelength was selected as 279 nm for both systems. The calibration curve was linear over a concentration range of 0.05-5 mu g mL(-1). The accuracy and precision of the method were determined to be 1.32-4.00 and 1.70-4.27 % ranges for RSD and RME, respectively. The absolute recovery of the drug was found to be 94.97 %. The developed method was successfully applied for the determination of ciprofloxacin in serum samples collected from a volunteer who had received 500 mg ciprofloxacin orally.