磁固相萃取-高效液相色谱-串联质谱法测定环境水样中的苯脲类除草剂残留

Determination of Phenylurea Herbicide Residues in Environmental Water by High Performance Liquid Chromatography-Tandem Mass Spectrometry Coupled with Magnetic Solid Phase Extraction

通过水热合成法制备磁性类沸石咪唑酯材料(Fe3O4@ZIF-8),采用扫描电子显微镜、透射电子显微镜和傅里叶变换红外光谱仪对该材料进行表征。将50mg Fe3O4@ZIF-8加入100mL水样中,于40℃振荡吸附10min后,将Fe3O4@ZIF-8进行磁分离,弃去水样,加入0.5mL乙腈,涡旋解吸1min,将洗脱液转移,重复解吸3次,合并洗脱液,用氮气吹至近干后用甲醇-0.1%(体积分数)甲酸溶液(6+4)混合溶液溶解并定容至500μL,经0.22μm有机滤膜过滤,滤液在Agilent Zorbax Eclipse XDB-C18反相色谱柱(50mm×3mm,1.8μm)上分离,以甲醇-0.1%(体积分数)甲酸溶液为流动相进行梯度洗脱,质谱分析中采用电喷雾离子源和多反应监测模式。4种苯脲类除草剂质量浓度均在0.01~20.0μg·L^(-1)内与峰面积呈线性关系,检出限(3S/N)为1.03~3.00ng·L-1。对空白水样进行加标回收试验,回收率在78.8%~106%之间,相对标准偏差(n=6)小于7.0%。

The magnetic zeolitic imidazole ester material（Fe3 O4 @ZIF-8）was prepared by hydrothermal synthesis method,and was characterized by scanning electron microscope,transmission electron microscope and Fourier transform infrared spectrometer.50 mg of Fe3 O4@ZIF-8 was added to 100 mL of water sample,and the mixture was shaken at 40 ℃ for 10 min of adsorption.After Fe3 O4@ZIF-8 was magnetically separated and the water sample was discarded,0.5 mL of acetonitrile was added and the mixture was vortexed for 1 min for desportion,the eluate was transferred,and desorption was repeated three times.The combined eluate was dried by nitrogen blowing,the residue was dissolved with a mixed solution of methanol and 0.1%（φ）formic acid solution（6＋4）,and the volume of the solution was made up to 500μL.After the solution was filtered through a 0.22μm organic filter,the filtrate was seperated on an Agilent Zorbax Eclipse XDB-C18 chromatographic column（50 mm×3 mm,1.8μm）,with a mixture of methanol and 0.1%（φ）formic acid solution as the mobile phase for gradient elution.Electrospray ion source and multi-reaction monitoring mode were selected in mass spectrometry analysis.Linear relationships were found between peak areas of 4 phenylurea herbicides and the corresponding mass concentrations in the same range of 0.01-20.0μg·L^（-1）,and the detection limits（3 S/N）were in the range of1.03-3.00 ng·L-1.Test for recovery was made by standard addition method to blank sample,giving results in the range of 78.8%-106%,with RSDs（n=6）less than 7.0%.