| Fluoroquinolones have the advantages of strong bacteriostasis,long drug effect and low resistance to drug resistance,however,with the widespread application of fluoroquinolones in animal husbandry and aquaculture,bacterial resistance and adverse reactions still occur one after another.These fluoroquinolones will enter the environment through human medicine,pharmaceutical factories,aquaculture,livestock and poultry breeding which cause sevre threats to the ecological environment and human health.The water environment is an important gathering place for fluoroquinolones and due to its long biological half-life and continuous entry into the environment,which causes its long-term existence.At present,there are many researches on fluoroquinolones residues in foods of animal origin such as broilers and aquatic products and the research on residuals in water environments is also receiving much attention.Therefore,it is very important to develop an accurate analytical method for the determination of fluoroquinolone residues in water.In this paper,the four fluoroquinolones(Ofloxacin,Norfloxacin,Ciprofloxacin,and Enrofloxacin)were studied and the method for the simultaneous determination of fluoroquinolones residues in water environment was developed by high performance liquid chromatography(HPLC).The details are as follows:(1)HPLC was used to optimize the determination of four fluoroquinolones assay conditions.The liquid chromatography separation was carried on Dianonsil? C18 column,the mobile phase was A(0.3%phosphoric acid-5%acetonitrile,adjusted the pH value with triethylamine to 4.00±0.01)-B methol,the gradient elution program was adopted(0-5 min,15%B,5-45 min,40%B,45-50 min,15%B),the flow rate was 0.8 ml/min and the column worked at 30℃,the injection volume was 10 μl,the wavelength was 278 nm.Under this condition,the retention time of four fluoroquinolones were 17.8 min(Ofloxacin),21.3 min(Norfloxacin),22.4 min(Ciprofloxacin)and 23.5 min(Enrofloxacin),respectively.The resolution of were 5.20、1.85 and 1.83,respectively.The resolution four fluoroquinolones were more than 1.5 and complete separation is achieved.(2)A quantitative analysis method for the simultaneous determination of four fluoroquinolones residues in water environment by HPLC was developed.The result showed that the standard curves for four fluoroquinolones were in linearity within the concentration range of OFL was 0.500-50.0 mg/L and NOR,CIP and ENR were 0.0500-50.0 mg/L.The r>0.9999 and the detection limit of four fluoroquinolones were between 0.0400 mg/L and 0.400 mg/L.The effects of DOC(C),Na+,K+,Mg2+,Ca2+,Cl-,SO42-and tetracycline hydrochloride on the experiment were examined.The water of South Lake was enriched and purified by Dispersive Liquid-Liquid Microextraction and the recoveries for four fluoroquinolones in water ranged between 95.8%and 109.2%with the RSD were less than 3.7%.The developed method in this research was high accuracy,good linearity,wide linear range and could be used for simultaneous identification and determination of the fluoroquinolones in water environment. |
