Determination of Norfloxacin in Water Supply System by Solid-phase Extraction and High Performance Liquid Chromatography

SPE-HPLC was used for determination of norfloxacin in water supply system.The optimal elution condition of C18 column was investigated,and the optimal chromatography conditions were selected on the basis of the peaks appearance time.They are as follows: the mobile phase is 0.01 mol/L sodium dihydrogen phosphate(pH adjusted to 2.4 with phosphoric acid) and methanol(70 ∶30,V/V),the column temperature is 20 ℃,the flow rate is 1.0 mL/min,and the detection wavelength is 272 nm.The calibration curve is linear in the range of 5 to 200 ng/mL.The recovery of standard addition is 100.5% to 101.5%,and RSD is 2.3% to 5.8%(n=6).The method is simple and accurate for determination of source water and coagulation treated water from water plant.