N,N-二甲基甲酰胺作为背景吸收物应用于非水毛细管电泳测定金属离子的研究

N,N-DIMETHYLFORMAMIDE AS CHROMOPHOR FOR CAPILLARY ELECTROPHORETIC DETERMINATION OF POTASSIUM AND SODIUM

对N,N-二甲基甲酰胺(DMF)作为背景吸收电解质用于高效毛细管电泳法分离测定钾、钠离子的可行性进行了研究.探讨了DMF乙腈溶液中加入硫酸、盐酸、高氯酸以及醋酸对分离效果以及灵敏度的影响.通过对比,发现使用3 mmol.L-1DMF+30 mmol.L-1硫酸缓冲体系分离效果最好,对Na+和K+的检测限分别为0.4和0.7μmol.L-1.本研究为进一步建立使用DMF为背景吸收物质的毛细管电泳法分离测定无机离子的方法奠定了基础.

The possibility of using DMF as background chromophore for determining sodium and potassium ions in capillary electrophoresis was investigated.Influences of buffer components,buffer concentration and detection wavelength on separation efficiency and sensitivity were studied.A buffer composed of 3 mmol·L-1 DMF and 30 mmol·L-1 sulfuric acid in acetonitrile was used.Sodium and potassium ions were successfully determined,within 5 minutes,with a detection limit of 0.4 and 0.7 μmol·L-1 respectively.Data suggest that DMF is a potential background chromophore for indirect detection of metal ions.