Abstract:A detection method of high-performance liquid chromatography (HPLC) coupled with fluorescence was developed for the determination of residues of three quinolones in seawater.pH of were water samples adjusted with dilute HCl followed by extraction and concentration through hydrophilic-lipophilic balance cartridges, and three antibiotic quinolone compounds were determined using external standard quantification method. The results showed that the detection limits of norfloxacin, ciprofloxacin and enrofloxacin were 2 μg/L, 1 μg/L and 1 μg/L respectively, and the quantitative limits were 6.6 μg/L, 3.3 μg/L and 3.3 μg/L respectively. The recoveries from natural seawater ranged from 71.9% to 85.3% when the three antibiotics were added at the concentration of 10 μg/L, 20 μg/L and 50 μg/L for norfloxacin, ciprofloxacin and enrofloxacin, respectively. The coefficients of variation within batches were equal or less than 10%, while that among batches were equal or less than 7%. The method has been successfully applied to the monitoring of the residues in the sea water samples from the Yellow Sea near Qingdao (from 36°40.303′N,121°8.939′ E to 35°39.36′N,119°52.433′E). Norfloxacin, ciprofloxacin and enrofloxacin were detected at mass concentrations of 6.20~982 μg/L, 55.2 μg/L and 11.6~55.4 μg/L respectively. The results showed that this method posessed high sensitivity and good reproducibility, and can be used for the detection of norfloxacin, ciprofloxacin and enrofloxacin in aquacultural seawater.
