高级检索

    QuEChERS前处理结合超高效液相色谱-串联质谱法同时测定土壤中11种农药的残留量

    Simultaneous Determination of Residues of 11 Pesticides in Soil by Ultra-High Performance Liquid Chromatography-Tandem Mass Spectrometry Coupled with QuEChERS Pretreatment

    • 摘要: 提出了QuEChERS前处理结合超高效液相色谱-串联质谱法同时测定土壤中有机磷类(敌敌畏、敌百虫、乐果、氧乐果)、氨基甲酸酯类(甲萘威、克百威、3-羟基克百威、涕灭威、涕灭威砜、涕灭威亚砜)和三嗪类(阿特拉津)等农药的残留量。取土壤样品10.00 g,加入10 mL水,涡旋混匀;加入15 mL含1%(体积分数)乙酸的乙腈溶液,涡旋2 min;加入QuEChERS萃取试剂,剧烈振摇5 min,离心5 min。分取5 mL上清液于含QuEChERS净化试剂的离心管中,剧烈振摇5 min,离心5 min。分取1 mL上清液,氮吹至近干,加入10 μL 混合内标溶液(2.0 mg·L−1),用50%(体积分数)甲醇溶液定容至1.0 mL,混匀,过滤,取滤液待测。以Accucore aQ色谱柱为固定相,以含5 mmol·L−1乙酸铵的1%(体积分数)甲酸溶液-甲醇为流动相体系进行梯度洗脱;分离后的目标物经电喷雾离子源正离子模式电离,多反应监测模式检测,内标法定量。结果表明:11种农药标准曲线的线性范围均为1.00~200.0 μg·L−1,检出限为1.7~8.2 μg·kg-1;对空白土壤样品进行3个浓度水平的加标回收试验,回收率为58.7%~98.3%,测定值的相对标准偏差为0.51%~8.2%。

       

      Abstract: A method for simultaneous determination of residues of organophosphorus (dichlorvos, tricholorfon, dimethoate, and omethoate), carbamate (carbaryl, carbofuran, carbofuran-3-hydroxy, aldicarb, aldicarb-sulfone, and cldicarb-sulfoxide) and triazine (atrazine) pesticides in soil by ultra-high performance liquid chromatography-tandem mass spectrometry coupled with QuEChERS pretreatment was proposed. The soil sample (10.00 g) was taken, and 10 mL of water was added. The mixture was swirled and mixed well, and 15 mL of acetonitrile solution containing 1% (volume fraction) acetic acid was added for swirling for 2 min. QuEChERS extraction reagent was added, and the mixture was shaken vigorously for 5 min. After centrifuging for 5 min, an aliquot (5 mL) of the supernatant was placed into a centrifuge tube containing QuEChERS purifying reagent, and shaken vigorously for 5 min, After centrifuging for 5 min, an aliquot (1 mL) of the supernatant was blown to near dryness by nitrogen, and 10 μL of the mixed internal standard solution (2.0 mg·L-1) was added. The mixed solution was made its volume up to 1.0 mL with 50% (volume fraction) methanol solution. After mixing well and filteration, the filtrate was taken to be determined. Accucore aQ column was used as the stationary phase, and 1% (volume fraction) formic acid solution containing 5 mmol·L-1 ammonium acetate-methanol was used as the mobile phase system for gradient elution. The separated targets were ionized by electrospray ion source with positive ion mode, detected by multiple reaction monitoring mode, and quantified by internal standard method. As shown by the results, the linear ranges of the standard curves for 11 pesticides were 1.00-200.0 μg·L-1, with detection limits in the range of 1.7-8.2 μg·kg-1. Test for recovery was made on the blank soil sample at 3 concentration levels, giving results in the range of 58.7%-98.3%, and RSDs of the determined values were in the range of 0.51%-8.2%.

       

    /

    返回文章
    返回