Determination of Fluoroquinolone Antibiotic in Milk with Graphene HF-SPME-HPLC

A method for determination of 6 fluoroquinolones in milk by graphene hollow solid phase microextraction coupled with high performance liquid chromatography(HPLC)was established. Graphene hollow fiber was prepared by sol-gel method using hollow fiber as template and graphene as reinforcement. Taking the maximum chromatographic peak area as an indicator,the factors affecting extraction efficiency were investigated. Results showed that,the best experimental conditions with acetonitrile(1.0 mL,5% formic acid)as disorption solution,sample solution volume 10 mL,pH7,NaCl 2.0 g,extraction temperature 50℃. Enrichment factor ranged from 14.2 to 30.8. The linear range of 6 fluoroquinolone drugs was 0.38~0.70 μg/L,the relative standard deviation was between 2.4% and 8.5%,and the recovery rate was 75.20%~95.4%. 2.1 μg/L norfloxacin and 4.8 μg/L ofloxacin were detected in brand milk 2 and market fresh milk respectively. This method with low matrix effect is sensitive,simple,accurate,and can be successfully applied to the detection of residual fluoroquinolones in milk.