固相萃取/高效液相色谱法对火龙果中手性苯醚甲环唑的分离测定

Separation and Determination of Chiral Difenoconazole in Dragon Fruit by Solid-phase Extraction Coupled with High Performance Liquid Chromatography

建立了固相萃取/高效液相色谱测定火龙果中手性苯醚甲环唑的方法。火龙果样品经乙腈提取,石墨化炭黑/氨基固相萃取柱净化后进行测定。实验考察了不同手性色谱柱、流动相组成、流速及进样体积对分离的影响,通过优化分离成功拆分了苯醚甲环唑对映体。优化的色谱条件为:Chrialcel IF-3手性柱为色谱柱,正己烷-乙醇(92∶8,体积比)为流动相,流速为1.0 m L/min,进样量为60μL。在上述条件下,4个对映体基本完全分离,分析时间不超过35 min。单个对映体在0.10~10 mg/L范围内呈良好的线性关系,检出限为0.025 mg/L。分别添加0.4、2.8 mg/kg两个水平的外消旋苯醚甲环唑,测得4个对映体的平均回收率分别为83.7%~99.3%和86.4%~91.6%,相对标准偏差分别为1.3%~7.2%和1.4%~3.1%。该方法的分离时间较短,分离效果好,灵敏度高,适用于火龙果等水果中手性农药苯醚甲环唑含量的测定。

A method was established for the determination of chiral difenoconazole in dragon fruit by solid-phase extraction coupled with high performance liquid chromatography.The dragon fruit samples were extracted with acetonitrile,and purified with carbon black/amino solid phase extraction column.Effects of different chiral columns,mobile phase compositions,flow rates and injection volumes on chiral separation were investigated.The optimized chromatographic conditions were as follows:the chromatographic column:IF-3 chiral column,mobile phase:n-hexane-ethanol(92∶8 by volume),injection volume:60μL,flow rate:1.0 mL/min.Under the optimized conditions,the four difenoconazole enantiomers were basically achieved baseline separation,and the analysis time was less than 35 min.There existed a good linearity for each enantiomer in the range of 0.10-10 mg/L,with a detection limit of 0.025 mg/L.The average recoveries for the chiral difenoconazole in dragon fruit at two spiked levels of 0.4 mg/kg and 2.8 mg/kg were in the ranges of 83.7%-99.3%and 86.4%-91.6%,with their RSDs of 1.3%-7.2%and 1.4%-3.1%,respectively.The developed method is rapid,accurate and sensitive,and is applicable for the determination of chiral difenoconazole residues in dragon fruit,etc.