固相萃取-超高效液相色谱-串联质谱法测定海水中13种三嗪类除草剂残留量

建立了固相萃取 超高效液相色谱 串联质谱法测定海水中13种三嗪类除草剂，样品抽滤后，经HLB固相萃取柱浓缩净化，洗脱液40 ℃下氮气吹至小于1 mL，然后用V（乙腈）∶V（水）=1∶1的溶液定容至1 mL，超声振荡1 min，样液经0.22 μm滤膜，在Acquity^TM UPLC HSS C18（2.1 mm ×100 mm×1.8 μm）色谱柱上进行梯度洗脱分离。流动相为乙腈和含有0.1%甲酸的5 mmol/L乙酸铵溶液，多反应监测模式下测定13种三嗪类除草剂残留量。13种三嗪类除草剂的线性范围为1~50 ng/L，相关系数为0.992~0.999；检出限为1 ng/L，定量限为2 ng/L，在2、5、10 ng/L 3个浓度水平加标平均回收率为65.8%~103%，相对标准偏差RSD为4.84%~15.2%。该方法灵敏度高、准确性好，适用于海水中除草剂类药物的检测。

Determination of Triazine Herbicides in Seawater Using Solid Phase Extraction-UPLC-MS/MS

The triazine herbicides in seawater were determined by solid phase extraction ultra performance liquid chromatography with electrospray ionization tandem mass spectrometry(UPLC-ESI-MS/MS). UPLC and MS/MS analytical conditions were examined and optimized critically by a series of experiments. Samples were filtrated and purified on the HLB solid phase extraction cartridges. The elution was collected and evaporated to less than 1 mL at 40 ℃ by nitrogen blow, then added to 1 mL acetonitrile and water (1∶1，V/V) and ultrasonic wave extraction for 1 min. After filtrated with 0.22 μm filter membrane, the residue was separated by Acquity^TMUPLC HSS C18 column (2.1 mm×100 mm×1.8 μm) using gradient elution separation. The mobile phase was a mixture of A (acetonitrile) and B (5 mmol/L ammonium acetate containing 0.1% formic acid) in a flow rate of 0.25 mL/min. Finally analytes were confirmed and quantified using MS/MS system in multiple reaction mode with triple quadrapole analyzer using positive polarity mode. The analytes show good linearity in the range of 1 ng/L to 50 ng/L with correlation coefficient from 0.992 to 0.999. The detection limit is 1 ng/L，and quantification limit is 2 ng/L. The average recoveries at three dose levels(2 ng/L, 5 ng/L and 10 ng/L) are 65.8%—103% with relative standard deviations from 4.84% to 15.2%. In addition, the method has merits of simplicity, sensitivity and rapidity, and can be used for simultaneous determination of triazine herbicides in seawater.