毛细管电泳-激光诱导荧光法测定草甘膦、草胺膦及氨甲基膦酸

建立了一种快速、有效的毛细管电泳分离-激光诱导荧光检测有机磷除草剂草甘膦、草胺膦和草甘膦的代谢物氨甲基膦酸的方法。将荧光衍生试剂5-(4, 6-二氯三嗪基)氨基荧光素(DTAF)成功用于衍生上述3种化合物。最佳衍生条件: DTAF的浓度为1.0 μmol/L,以50 mmol/L硼酸(pH 9.5)作为缓冲溶液,在30 ℃下反应40 min。以pH 9.5的30 mmol/L硼酸缓冲溶液(含15 mmol/L Brij-35)作为电泳背景电解质,3种衍生物得到基线分离。在优化的条件下,草甘膦、草胺膦、氨甲基膦酸的检出限分别为3.21、6.14和1.99 ng/kg。将该方法应用于环境水样和土壤中除草剂及代谢物的测定,回收率为91.3%～106.0%。该方法准确、灵敏,可满足环境样品中有机磷农药及其代谢物残留的检测要求。

Capillary electrophoresis analysis for glyphosate, glufosinate and aminomethylphosphonic acid with laser-induced fluorescence detection

A sensitive analytical method was developed for the simultaneous determination of glyphosate, glufosinate and aminomethylphosphonic acid by capillary electrophoresis with laser-induced fluorescence detection (CE-LIF). 5-(4,6-Dichlorotriazinyl) amino fluorescein (DTAF) was successfully applied to label the herbicides. The optimal derivatization reaction was carried out in boric acid buffer of pH 9.5 at 30 ℃ for 40 min. The baseline separation of the three derivatives could be accomplished using 30 mmol/L boric acid, 15 mmol/L Brij-35 (pH 9.5) as the running buffer. The detection limits (S/N=3) for the glyphosate, glufosinate and aminomethylphosphonic acid were 3.21, 6.14, 1.99 ng/kg, respectively. Finally, the method was successfully applied to the analysis of environmental samples, and the three compounds were measured without any interference from real samples. The recoveries of the compounds in these samples were 91.3%~106.0%. The method has the advantages of easiness and sensitivity, and can meet the requirement of the determination of the herbicide and metabolite residues in the environmental samples.