毛细管胶束电动色谱-质谱联用法测定农田水中的氨基甲酸酯类农药的研究

Simultaneous determination of N-methylcarbamate pesticides in farm water by micellar electrokinetic chromatography-electrospray ionization mass spectrometry

基于月桂酸可以直接进入电喷雾电离源且对氨基甲酸酯类农药在电喷雾电离源的电离强度没有明显的影响,建立了以月桂酸为表面活性剂的毛细管胶束电动色谱-电喷雾质谱联用(MEKC-ESIMS)同时测定7种氨基甲酸酯农药的新方法。在以30 mmol/L月桂酸和120 mmol/L氨水(含12%乙醇(V/V),pH9.5)缓冲溶液作为电解质,30%的异丙醇(V/V)(含2.0 mmol/L的乙酸)作为鞘液的条件下,各组分分离良好;结合固相萃取(SPE),各组分检出限为0.080～0.18μg/L,对农田水样进行测定,回收率为87.2%～93.8%,相对标准偏差为2.9%～8.5%。

A new method for the determination of N-methylcarbamate pesticides using lauric acid surfactant and ammonia as buffer by micellar electrokinetic chromatography-electrospray ionization mass spectrometry was developed.The samples were separated by an uncoated capillary（75μm×83 cm） on the operating voltage of 25 kV using 30 mmol/L lauric acid-120 mmol/L ammonia mixture containing 25% acetonitrile（pH 9.5） as the running buffer and 70% 2-propanol solution（containing 2 mmol/L acetic acid） as the sheath liquid.The baseline separation of seven compounds was achieved with satisfactory repeatability and sensitivity.The detection limit of each analyte varied from 0.080 to 0.18 μg/L with the preconcentration of AccuBOND-NH2 solid phase extraction column.The average recoveries of seven analytes from farm waste water ranged from 87.2% to 93.8% with relative standard deviations in the range of 2.9%~8.5%.The method is simple,rapid,accurate and suitable for the simultaneous determination of these herbicides in waste water.