QuEChERS-DLLME-高效液相色谱法测定蔬菜中溴虫腈和氟虫腈残留

建立同时检测蔬菜中溴虫腈和氟虫腈残留的QuEChERS-分散液液微萃取-高效液相色谱方法。样品用乙腈溶液提取，硫酸镁和氯化钠盐析后，加入N-丙基乙二胺和石墨化碳吸附净化，分散液液微萃取富集，用SunFire-C18反相色谱柱分离，以甲醇和水作为流动相梯度洗脱，二极管阵列检测器进行测定，外标法定量。并考察萃取剂和分散剂的类型及体积和萃取时间对萃取效率的影响。该方法在3.0～460 μg/kg范围内线性关系良好，相关系数（R2）不小于0.998 6，检测限0.70～0.86 μg/kg。3 个不同加标水平的平均回收率为90.5%～108.5%。相对标准偏差小于10%。结果表明，该方法简便、准确、并且成本较低，适用于蔬菜中溴虫腈和氟虫腈农药残留的测定。

Determination of Chlorfenapyr and Fipronil Residues in Vegetables by QuEChERS Combined with Dispersive Liquid-liquid Microextraction and High Performance Liquid Chromatography

A method was developed for simultaneous determination of the residues of chlorfenapyr and fipronil in vegetables
using QuEChERS combined with dispersive liquid-liquid microextraction and high performance liquid chromatography.
The sample was extracted with acetonitrile, salted out with MgSO4 and NaCl, cleaned up with N-propyl ethylenediamine
(PSA) and graphitized carbon, and concentrated by dispersive liquid-liquid microextraction (DLLME) before being analyzed
by HPLC. The separation of the target compounds was performed on a SunFire-C18 liquid chromatography column using
a mobile phase consisting of acetonitrile and water in a gradient elution mode and the matrix-matched external standard
calibration method was used for quantitation. Key DLLME experimental parameters including the type and volume
of extractant and disperser solvent and extraction time were optimized. This method had a good linearity in range of
3.0–460 μg/kg with correlation coefficients more than 0.998 6 (R2), and the limits of detectionwere in the range of
0.70–0.86 μg/kg. The average recoveries of chlorfenapyr and fipronil at three spiked concentration levels ranged from 90.5%
to 108.5%, with relative standard deviations (RSDs) less than 10%. This method is simple, accurate, low-cost, and applicable
for the determination of chlorfenapyr and fipronil residues in vegetables.