新型柱前衍生试剂分析草甘膦的高效液相色谱研究

摘要

以2，5二甲氧基苯磺酰氯（ DMOSC）为柱前衍生化试剂，建立了柱前衍生草甘膦的紫外检测反相高效液相色谱法，并优化了衍生化条件，得最佳条件：衍生温度35℃，时间15 min， pH 10�0，草甘膦与DMOSC的摩尔比为1∶6。HPLC分析条件：采用Kromasil C18柱，流速1�0 mL／min，柱温30℃，检测波长220 nm，流动相为甲醇-乙腈-磷酸盐缓冲溶液（0�02 mol／L、pH 5�5），三者的体积比为15∶5∶80。结果表明：草甘膦质量浓度在5～100μg／mL范围内线性关系良好，相关系数为0�9962，检测限为0�067μg／mL。实验表明该方法反应条件温和，灵敏度高，衍生产物稳定。%A derivatization method for the determination of glyphosate had been developed by using 2,5-dimethoxybenzenesulfonyl chloride�The optimized conditions of derivatization were as follows:reaction temperature 35 ℃,reaction time 15 min,solution pH value 10�0,the buffer reaction concentration 0�2 mol/L,and ratio of n( glyphosate) ∶n( o-nitrobenzenesulfonyl)= 1∶6�The chromatographic conditions were as follows:Kromasil C18 column(5 μm,4�6 ×250 mm),detection wavelength 220 nm,flow rate 1�0 mL/min,mobile phase A ( methanol)∶mobile phase B ( acetonitrile)∶mobile phase C ( phosphate buffer solution(PBS,pH 5�5,0�02 mol/L))= 15∶5∶80,isocratic elution.The calibration curve for glyphosate was linear ranging from 5 μg/mL to 100 μg/mL. The linear correlation coefficient was 0�996 2. The limit of detection was 0�067 μg/mL�The experimental result shows that the method is simple,rapid and reliable,and generally applicable.