柠檬酸水溶液生物亲和萃取-高效液相色谱法检测鱼肉样品中喹诺酮类药物残留

Determination of Quinolones Residues in Fish Samples with Citric Acid Aqueous Solution as Biological Affinity Extractant by High Performance Liquid Chromatography

用瑞利散射光谱法研究了鱼血清蛋白在不同浓度有机弱酸水溶液中的变性情况，并结合液相色谱法讨论了鱼肉样品中主要基体蛋白质与鱼油对喹诺酮类药物（QNs）残留提取的影响。研究表明，0．5mol／L柠檬酸水溶液可引起蛋白质缓慢且完全变性，导致蛋白质与QNs络合物离解，释放结合的药物。本研究以柠檬酸水溶液为生物亲和提取液，发展了一种高效样品前处理方法，结合高效液相色谱法测定了鱼肉中QNs残留。样品前处理过程为：称取适量匀浆后的鱼肉样品于聚四氟乙烯管中，以0．5mol／L柠檬酸水溶液提取QNs残留2次，分别取2mL提取液加入PSA和CleanertNH，混合颗粒吸附剂进行净化。本方法用于测定鱼肉样品中的依诺沙星、诺氟沙星、环丙沙星、洛美沙星、恩诺沙星和加替沙星，回收率为82．0％～95．2％，RSD为1．9％～5．8％，检出限为0．0055～0．016mg／kg。方法步骤简单、快速、可靠、环境友好。

Rayleigh scattering spectrometry was applied to study the degeneration of fish serum protein in different concentrations of weak organic acid aqueous solutions. The influence of proteins on extraction effieieneies of quinolones （QNs） residues from protein and oil matrixes of fish samples was also discussed by HPLC. In a 0.5 mol/L citric acid aqueous solution, a slow but full protein denaturation takes place, which causes the dissociation of QNs -protein complex. Based on the above results, with citric acid aqueous solution as biological affinity extraction system, an effective sample pretreatment method was developed for the analysis of QNs in fish samples by HPLC. The sample pretreatment procedure was as follows. Previously homogenized fresh fish samples was added to teflon tubes, then 0. 5 mol/L citric acid aqueous solution was used as extraction solvent, QNs residues were extracted twice from samples. The mixed granular adsorbents of primary secondary amine （PSA） and Cleanert NH2 were added in the extractant to eliminate the impurities. This method has been applied to the determination of 6 kinds of QNs （enoxacin, norfloxacin, ciprofloxacin, lomefloxacin, enrofloxacin and gatifloxacin） residues in the fish samples. The detection limits were in the range of 0. 0055-0. 016 mg/kg, and the spiked recoveries were 82.0% -95.2% with RSD 1.9% -5.8%. The method was simple, quick, reliable and environment friendly.