A novel capillary electrophoresis method for simultaneous determination of Cu and Pb has been developed in this paper.Cu（Ⅱ） and Pb（Ⅱ） ions were reacted with ABEDTA to form complex to achieve an ideal sensitivity of heavy metal complexes.The digestion solution of Rhizoma coptidis drug sample was purified by neutral Al_2O_3 column chromatography and the chromatographic behavior of metal-L complexes was investigated.The calibration curve was linear in the range of 5-60μg/mL for Cu^（2＋） and 5-25μg/mL for Pb^（2＋） with the correlation coefficients 0.9970 and 0.9972 for each（n = 5）.The average recoveries were 86.2%for Pb and 90.1%for Cu,while the relative standard deviations were 5.1%and 3.6%respectively.The method was successfully applied to determine Cu and Pb in R.coptidis drug samples.
Fan YunMengYing Qin WeiHeng LuXin Xin LiuJin Xin Liu
A new method for the analysis of copper and its speciation in Rhizoma coptidis was proposed using chelatometric dispersive liquid-liquid microextraction（cDLLME） followed by capillary electrophoresis. Dithizone was used as a chelating agent for extraction and carbon tetrachloride and ethanol were used as extraction and dispersive solvent,respectively.The calibration curve was linear in the range of 0.5- 20.0μg/mL with a correlation coefficient of 0.9990（n = 6） and the average recovery was in the range of 88.26%-94.44%.The method was successfully used to determine the total and water soluble copper in Rhizoma coptidis herbal medicine.The results suggested that it would be reasonable to setting the criterion of heavy metals in an herbal medicine according to the dosage forms.
