摘要
铜(I)-新铜试剂(NCP)-曙红Y(Eosin Y)能形成离子对三元络合物,其络合比为1:2:1。在氯仿中该络合物的λ_(max)=544nm,表观摩尔吸光系数ε=6.83×10~4 L mol^(-1)cm^(-1)。以柠檬酸盐作掩蔽剂,控制水相pH=4.5,相比(水相/氯仿)=2/1,可将络合物定量萃入氯仿中。一般常见的共存离子均不干扰测定,显色稳定性好,线性范围为0～5μg cu/5ml氯仿。方法灵救度高,选择性好。
A new sensitive extraction spectrophotometric method of the determination of trace copperhas been investigated. Cu(1) reacts with Neo-Cuproin and Eosin Y to form a coloured associ-tated complex which could be extracted into CHCl_3 and showed an absorption maximum at 544nm. The absorbance of Cu(1)-Ncp-Eosin Y complex increased greater than that of the Cu(1)-Ncp complex, Its E value at 544 nm was 6.83×10~4 1mol^(-l)cm^(-1).Beer's low is obeyed within the range of 0-5μg Cu per 5ml CHCl_3 solution. The method is simple. The sensitivity and the selectivity are very good. This method canbe used for the determination of trace copper in the Chinese Metria Madica.
关键词
铜
曙红Y
萃取光度法
Extraction-Spectrophotometry
neo-cuproin and eosin y
