Water-compatible molecularly imprinted polymers for selective extraction of ciprofloxacin from human urine

Water-compatible molecularly imprinted polymers (MIPs) were prepared in water–methanol systems for selective extraction and separation of ciprofloxacin from human urine samples. Molecular recognition properties, binding capability, and chromatographic applications of the MIPs were evaluated and the results revealed the obtained MIPs have high affinity for ciprofloxacin in aqueous environment and the selectivity can be easily controlled by adjusting the pH of mobile phase. After centrifugation, the urine samples were directly injected into the MIPs column and ciprofloxacin could be selectively retained on the column while other biological matrixes were quickly washed out. Good linearity was obtained from 0.1 to 100 mg L−1 (r = 0.999) with the relative standard deviations less than 3.6%. The limit of detection of the method was 0.03 μg/mL and the recoveries were more than 94.5% at three different concentrations. Moreover, by increasing the injection volume, the detection limits of the method could be improved more than 100-folds.