A simple, rapid sensitive and accurate ultra performance liquid chromatography tandem mass spectrometry (UPLOMS/MS) method was developed for the simultaneous determination of five currently used herbicides in soil. The sample preparation using the modified QuEChERS (quick, easy, cheap, effective, rigged, and safe) method completed the extraction and clean-up steps in one procedure. In this none buffer QuEChERS method, samples were extracted with acetonitrile, cleaned up with primary secondary amine (PSA) and C18 sorbent, then centrifugated and filtrated before detection. The pretreatment method was simple, rapid and effective and can meet the detection requirements. The UPLC-MS/MS method was performed on Waters ACQUITY UPLCM BEH C18 (50 mm×2. 1 mm I. D. , 1. 7 μm) and the column temperature was 30 ℃, the gradient elution with methanol and pure water as the mobile phase and the flow rate was 0. 25 mL/min. The positive elec-trospray ionization (ESI+) source under the multiple reaction monitoring (MRM) mode and external standard method were used for quantification. The results showed that the correlation coefficients up to 0. 9984 were obtained across a concentration range of 0. 5 - 200 μg/L. The limits of detection (LOD) ranged 0. 005 - 0. 020 μg/kg (S/N=3), the limits of quantification (LOQ) were 0. 017 -0.067 μg/kg (S/N= 10). The method was validated with soil samples spiked at two fortification levels (4 μg/kg and 40 μg/kg) and recoveries were in the range of 75. 4% - 98. 5% with relative standard deviations (RSD) of 3. 2%-11. 8%.%建立了超高效液相色谱串联质谱法(UPLC-MS/MS)简单、快速、灵敏、准确地同时测定土壤中5种常用除草剂多残留量的方法.样品经改进的QuEChERS(快速、简单、廉价、高效、灵活和安全)方法一步完成萃取净化,未使用缓冲盐溶液,经乙腈萃取,N-丙基乙二胺(PSA)和C18吸附剂填料净化,离心后直接过膜上机检测,萃取和净化的效果满足检测要求.UPLC-MS/MS方法采用Waters ACQUITY UPLCTM BEH C18 (50 mm×2.1 mmi.d,1.7μm)色谱柱,柱温30℃,流动相为甲醇和水,梯度洗脱,流速0.25 mL/min,电喷雾电离源正离子(ESI+)多反应监测(MRM)模式检测,外标法定量.5种常用除草剂在0.5～200 μg/L范围内线性关系良好,相关系数为0.9947～0.9984.在4和40μg/kg水平下的平均加标回收率为75.4％～98.5％；相对标准偏差为3.2％～11.8％；方法的检出限(S/N=3)为0.005～0.020 μg/kg,定量限(S/N=10)为0.017～0.067 μg/kg.
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