Running buffers for determination of chromium(VI)/(III), cobalt(II) and zinc(II) in complex matrices by capillary electrophoresis with contactless conductivity detection

详细信息	查看全文 | 推荐本文 |

• 作者：Li-Shi Wang ; Shui-Feng Zhang ; Zhi Dang ; Xiao-Xiao Liu ; Xin-Jian Huang ; Ming-Wei Xiao ; Zuan-Guang Chen
• 关键词：Capillary electrophoresis ; Contactless conductivity detection ; Chromium(VI)/(III) ; Cobalt(II) ; Zinc(II) ; Speciation
• 刊名：Talanta
• 出版年：2007
• 期刊代码：106_00399140
• 类别：ch
• 出版时间：15 June 2007
• 卷：72
• 期：4
• 页码：1342-1347
• 文件大小：402 K

摘要

Complex matrices and rather high acidity in environmental samples are often the impelling challenges for the used running buffers of capillary electrophoresis. Twelve binary acid–base buffers were evaluated for separation of Cr(VI)/Cr(III), Co²⁺ and Zn²⁺ in a sample containing various salts by capillary electrophoresis with contactless conductivity detector. The malic acid (MA) systems including MA–His (histidine), MA–Arg (arginine) and MA–Tris (tris(hydroxymethyl)aminomethane) were selected as the candidates with powerful separation efficiency and good response sensitivity. In the MA–Tris buffer, optimization were further carried out in terms of the pH value and the concentration of MA, and the optimal conditions were obtained as 6 mM MA–Tris and 2 mM 18-crown-6 at pH 3.5. Furthermore, a real application was demonstrated by analyzing the plating rinse water (pH 0.8), in which the Ca²⁺, Na⁺, Cr(VI)/Cr(III), Co²⁺ and Zn²⁺ were all detected by adjusting at pH 3.5 with 5%(v/v) diluent ammonia. Both the cations, e.g., K⁺, Ca²⁺, Na⁺, Mg²⁺, and the common high concentration anions in the sample, e.g., Cl⁻, SO₄²⁻ and NO₃⁻ did not cause any disturbance to the concerned analytes.