多壁碳纳米管固相萃取/超高效液相色谱-串联质谱测定茶油中12种氨基甲酸酯类农药

建立了多壁碳纳米管(MWCNTs)为吸附剂的固相萃取净化/超高效液相色谱-串联质谱(UPLC-MS/MS)检测茶油中12种氨基甲酸酯类农药残留的快速分析方法。样品经乙腈超声提取,MWCNTs固相萃取小柱净化,以乙腈进行洗脱,旋蒸浓缩后以0.1%乙酸-乙腈(5∶5,体积比)定容,采用UPLC-MS/MS多反应监测模式(MRM)测定,外标法定量。考察了提取方式、吸附材料类型、洗脱溶剂用量等因素对目标物萃取效率的影响。在优化实验条件下,MWCNTs固相萃取小柱对茶油样品的净化效果理想。12种氨基甲酸酯类农药在0.005～0.1μg/mL范围内线性关系良好,相关系数(r)均不小于0.998 88;在0.01、0.025、0.05 mg/kg加标水平下,12种目标物的平均回收率为78.3%～116%,相对标准偏差为2.6%～12%,方法的定量下限为0.2～3.0μg/kg。

Determination of 12 Carbamate Pesticide Residues in Camellia Oil by Ultra Performance Liquid Chromatography-Tandem Mass Spectrometry with Multi walled Carbon Nanotubes Solid phase Extraction

A rapid method of ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS )was developed for the simultaneous determination of 12 carbamate pesticide residues in camellia oil based on solid-phase extraction with multi-walled carbon nanotubes (MWCNTs )as adsorbent.The samples were ultrasonically extracted with acetonitrile,then cleaned up with a MWCNTs SPE column.After elution with acetonitrile and concentration,the extracts were adjusted to the volume with a mixture of 0.1 % acetic acid-acetonitrile (5 ∶ 5,by volume ).The target compounds were determined by UPLC-MS/MS in multiple reaction monitoring (MRM )mode,and quantified by external standard method.Effects of extraction methods,types of sorbents and dosages of elution solvents on the extraction efficiency were investigated.Under the optimal conditions,the MWCNTs solid-phase extraction cartridge has an ideal purification effect on 12 carbamate pesticides in camellia oil,which could effectively eliminate the matrix effect.There were good linear relationships for 12 carbamate pesticides in the range of 0.005-0.1 μg/mL with their correlation coefficients (r ) not less than 0.998 88.Average recoveries for 12 targets at spiked levels of 0.01,0.025 and 0.05 mg/kg ranged from 78.3 % to 116 % with relative standard deviations of 2.6 %-12 %.The limits of quantitation (LOQ )of the method were in the range of 0.2-3.0 μg/kg.