QuEChERS-气相色谱-串联质谱法测定葡萄等浆果中7种酰胺类杀菌剂残留量

QuEChERS-GC-MS/MS Determination of Residual Amount of 7 Amide Fungicides in Berries

采用QuEChERS方法结合气相色谱-串联质谱法测定浆果中7种酰胺类杀菌剂(甲霜灵、呋霜灵、苯霜灵、环酰菌胺、苯酰菌胺、环氟菌胺、噻呋酰胺)残留量。取5.0g的浆果样品依次用1%(体积分数)乙酸-乙腈溶液20mL萃取和5g无水硫酸镁盐析后,萃取液经N-丙基乙二胺、十六烷基硅烷(C18)、石墨化炭黑净化,在6 000r·min^-1转速下离心;取上清液在60℃下氮吹至近干,用正己烷定容至1.0 mL,过0.2μm滤膜,滤液在DB-5MS色谱柱(30 m×0.25 mm,0.25μm)、程序升温的条件下进行色谱分离,并在多反应监测(MRM)模式下进行质谱分析,采用内标法定量。7种酰胺类杀菌剂的线性范围均为0.04~4.0mg·L^-1,检出限(3S/N)为0.001~0.003mg·kg^-1。对葡萄样品进行3个浓度水平的加标回收试验,测得回收率为86.2%~100%;测定值的相对标准偏差(n=6)为1.6%~4.1%。

An analytical method for determination of 7 residual amount of amide fungicides(metalaxyl,furalaxyl,benalaxyl,fenhexamid,benzoyl amine,cyflufenamidand thifluzamide)in berries by QuEChERS-GC-MS/MS was established in the work.5.0 g of the berry samples were extracted by 20 mL of 1%(volume fraction)acetic acid-acetonitrile solution,then 5 g anhydrous magnesium sulfate was used to salt out.The extracted solution obtained was purified by N-propyl ethylenediamine,C18 and graphitized carbon black,and centrifuged at 6 000 r·min^-1 rotation speed.The supernatant was taken and evaporated to near-dryness by N2-blowing at 60 ℃,and dissolved and diluted to 1.0 mL with n-hexane,then filtered through a 0.2μm filter membrane.The filtrate was introduced to DB-5 MS chromatographic column(30 m×0.25 mm,0.25μm)and separated under the programmed temperature elevation,and then analyzed by MS/MS with MRM mode.Internal standard method was used in quantitative analysis.Linearity ranges of 7 amide fungicides were found in the same range of 0.04-4.0 mg·L^-1,with detection limits(3 S/N)of 0.001-0.003 mg·kg^-1.Tests for the spiked recovery were made at 3 concentration levels for the grape samples,giving results of recovery ranged from 86.2%to 100%.Values of RSDs(n=6)found were in the range of 1.6%-4.1%.