基于离子液体-双水相体系同时测定蜂蜜中3种三嗪类除草剂残留

采用胆碱离子液体与非离子表面活性剂Triton x-100(Tr)建立环境友好的双水相体系(ABS),用于萃取蜂蜜中的西玛津、氰草津和阿特拉津3种三嗪类除草剂,并结合高效液相色谱法(HPLC)对除草剂残留进行测定。考察了相组成和温度对ABS形成的影响,结果表明离子液体中阴离子的碳链越长,ABS的双相区越小,而温度对ABS的双相区无显著影响。采用Tr-醋酸胆碱([Ch][Ac])双水相体系对待测除草剂的分配行为进行研究,发现待测组分主要富集于表面活性剂相。除草剂的分配系数随着Tr质量分数的增加而降低,而随着[Ch][Ac]质量分数的增加而增加,表明离子液体的盐析能力对双水相体系的形成起主导作用。在优化的萃取条件下,待测组分的线性范围为0. 1～20. 0 mg/L,相关系数(r^2)不低于0. 992,定量下限为0. 005～0. 02 mg/kg,平均加标回收率为75. 0%～114%,相对标准偏差为5. 2%～7. 6%。该方法适用于蜂蜜样品中此3种除草剂残留的分析。

Simultaneous Determination of Three Triazine Herbicides Residues in Honey Samples Based on Aqueous Biphasic System with Ionic Liquid

Aqueous biphasic system(ABS) based on the surfactant(triton x-100,Tr) and cholinium ionic liquids were developed for the extraction of triazine herbicides in honey samples. The influences of phase compositions and temperature on the formation of ABS were investigated. The biphasic region of ABS decreased with the increase of carbon chains of the anions in ionic liquids,but made no distinct difference with the increase of temperature. The partitioning behaviors of the selected herbicides were investigated using the Tr-choline acetate([Ch][Ac]) ABS. Results showed that the analytes were mainly concentrated in the surfactant-rich phase. The partition coefficients of the herbicides decreased with the increase of Tr mass fractions,while increased with the increase of [Ch][Ac]concentrations,which indicated that the salting-out ability of the ionic liquid played an important role in the system formation. Under the optimized conditions,there were good linear relationships for the selected herbicides over the concentration range of 0. 1-20. 0 mg/L with correlation coefficients(r^2) not less than 0. 992. The limits of quantitation for the analytes ranged from 0. 005 mg/kg to 0. 02 mg/kg,and the average recoveries were between 75. 0% and 114% with RSDs of 5. 2%-7. 6%. The proposed method is suitable for the determination of the target herbicides in honey samples.