水兼容性分子烙印固相萃取-高效液相色谱法测定鸡肉中氟喹诺酮类药物残留

目的：建立分子烙印固相萃取-高效液相色谱测定鸡肉中氟喹诺酮类药物残留的新方法。方法：以甲基丙烯酸为功能单体，恩诺沙星为模板分子，在强极性溶剂甲醇-水体系中制备分子烙印聚合物，考察和评价分子烙印聚合物的特性。鸡肉样品经乙腈提取浓缩后过分子烙印固相萃取柱，乙腈-三氟乙酸(99:1，V/V)洗脱液由高效液相色谱分离和荧光法检测。结果：高亲合力的结合位点的解离常数为Kd1=7.19×10-5 mol/L，最大表观结合位点数Qmax,1=110.19μmol/g；低亲和力结合位点的解离常数为Kd2=2.44×10-3mol/L，最大表观结合位点数Qmax,2 = 965.51μmol/g。氧氟沙星、诺氟沙星、环丙沙星和恩诺沙星等氟喹诺酮类药物的校准曲线在1.0～500 μg/kg范围内呈良好的线性关系(r≥0.9991)，检出限(S/N=3)为0.06～0.09μg/kg，平均回收率为75.4%～86.4%(n=3)，相对标准偏差小于6%。结论：以水兼容性分子烙印固相萃取-高效液相色谱法可实现氟喹诺酮药物的有效分离和灵敏测定。

Water-compatible Molecularly Imprinted Solid Phase Extraction-HPLC for Determination of Fluorouinolones Residues in Chicken

Objective: To establish a new method for the effective separation and sensitive detection of four fluorouinolones (ofloxacin, norfloxacin, ciprofloxacin and enrofloxacin) residues in chicken by using molecularly imprinted solid phase extraction-HPLC. Methods: Water-compatible molecularly imprinted polymers (MIPs) were synthesized in methanol-water systems with enrofloxacin as templates and methacryclic acid as functional monomers, and their characteristics were investigated and evaluated. The chicken samples were extracted with acetonitrile, purified by molecularly imprinted solid-phase extraction column with mixture of acetonitrile and trifluoracetic acid (99:1, V/V) as elution solution, and then the eluent was separated by HPLC and detected by fluorescence method. Results: The MIPs have good adsorption specificity to six fluoroquinolones. For the higher affinity site, Kd1 is 7.19×10-5 mol/L, and Qmax,1 is 110.19 μmol/g; For the lower affinity site, Kd2 is 2.44×10-3 mol/L, and Qmax,2 965.51 μmol/g. Excellent linear relationships may be obtained in the range of 1.0 to 500 μg/kg (r ≥ 0.9991). The determination limits (S/N= 3) are in the range of 0.06 to 0.09 μg/kg. The mean recoveries range from 75.3% to 88.5% with relative standard deviations below 6% (n = 3). Conclusion: The effective separation and sensitive detection of the four fluorouinolones in chicken can be archived by using the water-compatible molecularly imprinted solid phase extraction-HPLC.