改进的QuEChERS结合HPLC-MS/MS快速测定土壤中硝基酚类化合物

Rapid determination of nitrophenols in soil by improved QuEChERS method combined with HPLC-MS/MS

本文提出了土壤样品改进的QuEChERS萃取前处理方法,并结合液相色谱-质谱法测定土壤中4种酚类化合物(4-硝基酚,2,4-二硝基酚,2,6-二硝基酚,2,4,6-三硝基酚)含量的方法。1 g土壤样品,置于15ml塑料离心管中,加入2 mL纯水浸润30 min,后加入2 mL甲醇,室温下涡旋3 min,后使混合液以4000 r·mi^(-1)的转速离心3 min。取1 mL上层清液,用0.22μm滤膜过滤后直接上机检测,使用多反应监测(MRM)模式检测,电喷雾电离源负离子模式(ESI-),外标法定量。实验结果表明,4种硝基酚类化合物在2.0~100.0μg·L^(-1)的浓度范围的线性相关系数均大于0.998;方法检出限(MDL)为1.76~4.19μg·kg^(-1);以实际土样为基体,加入低中高3个浓度水平的标准溶液进行加标回收试验,加标回收率在85.6%~112%,相对标准偏差(n=6)在1.46~6.86%之间。

A liquid chromatography-mass spectrometry method was proposed for the determination of four nitrophenolsin soil(4-nitrophenol,2,4-dinitrophenol,2,6-dinitrophenol,2,4,6-trinitrophenol).1 g of soil sample was placed in a 15ml plastic centrifuge tube,soaked with 2 mL of pure water for 30 minutes,then added with 2 mL of methanol,swirled at room temperature for 3 minutes,and centrifuged at a rotating speed of 4000 r·min'for 3 minutes.The supernatant was directly tested on the machine after filtered by a 0.22μm filter membrane.Electrospray ionization source negative ion mode(ESI-)and multiple reaction monitoring(MRM)mode were used for detection,and the external standard method was used for quantification.From the results we can concluded that the linear correlation coefficients of the four nitrophenolic compounds were all greater than 0.998 in the concentration range of 2.0~100.0μg·L^(-1);the method detection limit(MDL)was 1.76~4.19μg·kg^(-1);The matrix was spiked at three different standard levels for determination of recovery and accuracy and the recovery rate was between 85.6%and 112%,and the STD(n=6)was 1.46~6.86%.