【摘要】 基于月桂酸可以直接进入电喷雾电离源,且对三嗪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8种三嗪类农药的新方法。在以40 mmol/L月桂酸和140 mmol/L氨水作为缓冲溶液、70%的异丙醇(含3.0mmol/L的醋酸铵)作为鞘液的条件下,各组分分离良好;结合固相萃取(SPE)技术对农田水样进行测定,各组分检出限为0.040~0.10μg/L;回收率在87.2%~97.3%之间。更多还原

【Abstract】 A novel method for the determination of triazine herbicides,using lauric acid and ammonium hydroxide as buffer system,by micellar electrokinetic chromatography-electrospray ionization mass spectrometry(MEKC-ESIMS)was developed.The effect of some key factors,such as concentration of lauric acid and ammonium hydroxide,addition of organic solvent,capillary temperature,applied voltage and the composition of sheath liquid on the separation and ionization of herbicides was investigated.Under the optimized conditions,40 mmol/L lauric acid and 140 mmol/L ammonium hydroxide composed running buffer,a mixture of isopropanol and water(70∶30) with 3 mmol/L ammonium acetate as the sheath liquid,the baseline separation of eight triazine herbicides was achieved with satisfactory repeatability and high sensitivity.The detection limit of each analytes varied from 0.040 to 0.10 μg/L with the preconcentration of ODS-C18 solid phase extraction column.The average recoveries of eight herbicides from farm water ranged from 87.2% to 97.3% for all with RSDs below 8.0%(n=5).The method is simple,rapid,accurate and suitable for the simultaneous determination of these herbicides in water.更多还原