Basheer Chanbasha, Lee Hian Kee
Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore.
Electrophoresis. 2007 Oct;28(19):3520-5. doi: 10.1002/elps.200700248.
A facile, sensitive, and selective method was developed for the simultaneous separation and determination of copper(I) [Cu(+)] and copper(II) [Cu(2+)] ions using CE with direct UV detection. The copper ions were complexed with a 1.5 mM bicinchoninic acid disodium salt solution at pH 8.7 prior to analysis. Acetate buffer (2 mM) was used as the CE running buffer. Parameters affecting CE separation such as sample pH, applied voltage, concentration of complexing agent, nature of the buffer solution, and interferences by other metal ions, were evaluated. The LODs for Cu(+) and Cu(2+) were 3.0 and 2.5 microg/mL (S/N = 3), respectively. The developed method allows the simultaneous determination of Cu(+) and Cu(2+) in less than 5 min with RSDs of between 5.3 and 9.5% for migration time and between 3.4 and 9.7% for peak areas, respectively. At optimum conditions, the percentage recoveries of Cu(+) and Cu(2+) were found to be 99.4 and 99.5%.
开发了一种简便、灵敏且具有选择性的方法，用于使用带直接紫外检测的毛细管电泳同时分离和测定铜（I）[Cu(+)]和铜（II）[Cu(2+)]离子。分析前，铜离子在pH 8.7条件下与1.5 mM的二辛可宁酸二钠盐溶液络合。使用醋酸盐缓冲液（2 mM）作为毛细管电泳运行缓冲液。评估了影响毛细管电泳分离的参数，如样品pH值、施加电压、络合剂浓度、缓冲溶液性质以及其他金属离子的干扰。Cu(+)和Cu(2+)的检测限分别为3.0和2.5 μg/mL（信噪比 = 3）。所开发的方法能够在不到5分钟的时间内同时测定Cu(+)和Cu(2+)，迁移时间的相对标准偏差在5.3%至9.5%之间，峰面积的相对标准偏差在3.4%至9.7%之间。在最佳条件下，Cu(+)和Cu(2+)的回收率分别为99.4%和99.5%。
