柱切换在线前处理法鉴别地沟油的离子色谱研究  

Distinguishing illegal cooking oils by ion chromatography with column-switching on-line sample pretreatment

作　　者：赵训燕 倪承珠 朱彬和 张培敏[1] 张嘉捷[1] 陈素清[3] 朱岩[1,2] 

机构地区：[1]浙江大学化学系,浙江杭州310028 [2]浙江大学浙江省微量有毒化学物健康风险评估技术研究重点实验室,浙江杭州310028 [3]台州学院制药与化学工程学院,浙江台州317000

出　　处：《浙江大学学报（理学版）》2016年第2期220-225,共6页Journal of Zhejiang University（Science Edition）

基　　金：国家重大科学仪器设备开发专项(2012YQ09022903);浙江省自然科学基金资助项目(Y12B050014;LQ13B050001;LY12B05003)

摘　　要：建立了同时检测食用油及地沟油中的无机阴离子（F^-、Cl^-、SO4^2-）和有机酸（CH3CO2^-、CHO2^-）的离子色谱柱切换在线前处理方法.采用一根NG1反相色谱柱作为前处理柱在线去除样品中的水溶性有机基质,通过柱切换技术,由淋洗液将柱内富集的离子带至阴离子分析柱中分离,从而达到在线前处理的目的.在优化的色谱条件下,被分析离子浓度在0.05-10mg·L^-1时,线性相关系数均大于0.999 0;进样量25μL,方法的检出限为4-41μg·L^-1（信噪比S/N=3）;加标回收率在75.6%-87.7%;相对标准偏差在0.85%-2.34%（n=6）;实验结果表明,地沟油中甲酸和乙酸的含量明显高于食用油.本方法对食用油和地沟油的鉴别具有较好的实用价值,适用于食用油及地沟油中常规阴离子和有机酸的同步检测,具有快速、灵敏、选择性好等优点.The ion chromatography with on-line sample pretreatment using column-switching technique is applied to the simultaneous analysis of the conventional inorganic anions and organic acids in edible oils and illegal cooking oils.In this work,apolymer-based reversed-phase column was used as the pretreatment column.Via column-switching technique,sample solution with target ions were eluted from a collection loop to the analytical columns with matrix eliminated on-line.A series of standard solutions consisting of target ions of various concentrations from 0.05 to 10mg·L^-1 are analyzed,with a correlation coefficient r≥0.9990 and a satisfactory repeatability（RSD≤2.34%,n=6）.The limits of detection are in the range from 4to 41μg·L^-1 based on S/Nof 3and the 25μL injection volume.The average spiked recovery rates are between 75.6% and 87.7%.The result shows that the concentration of acetate and formate are significantly higher in the illegal cooking oils than edible oils.The on-line sample pretreatment IC system is convenient and practical for the determination of conventional inorganic anions and organic acids in edible and illegal cooking oil samples.

关 键 词：离子色谱 柱切换 常规阴离子 有机酸 

分 类 号：O657.7[理学—分析化学]