一种用于鸡蛋中氯霉素残留测定的吡啶类离子液体双水相体系

Determination of Chloramphenicol in Eggs Using an Aqueous Two Phase Systems of Pyridine Ionic Liquid and Salt

建立了由亲水性离子液体N-乙基吡啶溴化盐([EPy]Br)和K2HPO4形成的双水相体系对鸡蛋中痕量氯霉素(CAP)检测的高效液相色谱方法。优化了离子液体[EPy]Br和K2HPO4成相的条件,研究了萃取CAP的最佳体系。采用混合溶液(pH=7磷酸盐溶液,NaCl溶液,甲醇)提取样品,离子液体双水相体系富集,V(甲醇):V(水)=30:70为流动相,流速1.0mL/min,UV检测器,检测波长278nm,柱温25℃,进样量20μL。对鸡蛋中氯霉素残留进行了测定,在0.05～15mg/L范围内,CAP的响应峰面积与其相应浓度呈良好相关性(r=0.9994)。不同浓度的回收率为90.3%～101.7%,相对标准偏差为1.7%～2.6%。本该法检测鸡蛋中氯霉素残留具有干扰小、速度快、灵敏度高等优点。最低检出限为1μg/kg。

A new high performance liquid chromatographic method for extracting and separating chloramphenicol （CAP） in eggs with aqueous two phase system （ATPS） formed by a room temperature hydrophilic ionic liquid（IL） [ EPy] Br （N-ethyl pyridine bromide） and salt （ K2HPO4 ） was developed. The condition of phase formation of ionic liquid （ [ EPy] Br） and salt （ KzHPO4 ） has been optimized, the best system for extracting CAP was studied. The sample was extracted by the mixed solution of NaCl, phosphate buffer solution and methanol. Then the extract was enriched by IL-ATPS. The separation of the CAP and IL in egg was achieved using methanol： water （30：70, V/V） as mobile phase with a flow rate of 1.0 mL/min at 25 ℃ under UV deteetor at 278 nm and an injection volume of 20 μL. The peak area of CAP and concentration achieved good linear relation ranged from 0.05 mg/L - 15 mg/L（ r =0. 9994）. The recovery of different concentrations CAP was 90.3% -101.7% ,relative standard deviation was 1.7% -2.6%. The method was reliable, rapid and sensitive for the determination of CAP in eggs. The lowest detection limit was 1μg/kg.