López C E, Castro J M, González V, Gonzalez E, Pérez J, Seco H M, Fernández J M
Departamento de Química Analítica, Escuela Universitaria Politécnica de Ferrol, Universidade da Coruña, Spain.
J Chromatogr Sci. 1998 Jul;36(7):352-6. doi: 10.1093/chromsci/36.7.352.
Trace metals determination in aqueous samples can be readily accomplished by capillary electrophoresis (CE) via indirect absorbance detection. A method for the separation of metal ions is presented and applied to the determination of seven metals in algal solution samples. 2-Hydroxyisobutyric acid background electrolyte (BGE) containing UV CAT-1 (an ultraviolet-absorbing amine) is used to perform capillary ion analysis. Acetic acid is used to adjust the pH value of BGE to 4.4. All ions can be separated in less than 15 min. All peaks are well separated and baseline resolved (i.e., no peaks overlapped). This work presents the applicability of CE to the quantitative analysis of algal solution samples and shows the adsorption process of seven metals in solution (Mn, Cd, Cr, Ni, Zn, Pb, Cu) to Chlorella vulgaris. The innovation of the application of CE in the determination of metals bound by Chlorella vulgaris is shown to be an improvement of the pH over what has been published previously. The detection limit is in the range of 13 (Mn) to 102 (Pb) ppb with electrokinetic injection mode (15 kV, 7 s). Reproducibility was 1.4% for the migration time, better than 5% for peak area for four of the metal ions (Cr, Mn, Cd, and Cu), and lower than 5% for the other three (Ni, Zn, and Pb). Calibration curves are linear for most ions in the 10(-7)-10(-5)M range (correlation coefficient r2 = 0.9933-0.9986) using electrokinetic injection mode.
通过间接吸光度检测，利用毛细管电泳（CE）可轻松完成水样品中痕量金属的测定。本文提出了一种金属离子分离方法，并将其应用于藻类溶液样品中七种金属的测定。使用含有UV CAT - 1（一种紫外线吸收胺）的2 - 羟基异丁酸背景电解质（BGE）进行毛细管离子分析。用乙酸将BGE的pH值调节至4.4。所有离子可在不到15分钟内分离。所有峰均分离良好且基线分离（即无峰重叠）。这项工作展示了CE在藻类溶液样品定量分析中的适用性，并显示了溶液中七种金属（锰、镉、铬、镍、锌、铅、铜）对普通小球藻的吸附过程。CE在测定普通小球藻结合金属中的应用创新在于pH值比之前发表的有所改进。电动进样模式（15 kV，7 s）下的检测限在13（锰）至102（铅）ppb范围内。迁移时间的重现性为1.4%，四种金属离子（铬、锰、镉和铜）的峰面积重现性优于5%，其他三种（镍、锌和铅）低于5%。使用电动进样模式时，大多数离子在10(-7)-10(-5)M范围内校准曲线呈线性（相关系数r2 = 0.9933 - 0.9986）。
