Ramachandraiah C, Rajesh Kumar J, Janardhan Reddy K, Lakshmi Narayana S, Varada Reddy A
Analytical Chemistry Division, Department of Chemistry, Sri Venkateswara University, Tirupati-517 502, Andhra Pradesh, India.
J Environ Manage. 2008 Sep;88(4):729-36. doi: 10.1016/j.jenvman.2007.03.033. Epub 2007 May 4.
Nickel(II) reacts with N-ethyl-3-carbazolecarboxaldehyde-3-thiosemicarbazone (ECCT) and forms a yellow colored complex, which was extracted into n-butanol from sodium acetate and acetic acid buffer at pH 6.0. The absorbance value of the Ni(II)-ECCT complex was measured at different intervals of time at 400 nm, to ascertain the time stability of the complex. The extraction of the complex into the solvent was instantaneous and stable for more than 72 h. The system obeyed Beer's law in the concentration range of 1.2-5.6 microg ml(-1) of nickel(II), with an excellent linearity and a correlation coefficient of 0.999. The molar absorptivity and Sandell's sensitivity of the extracted species were found to be 1.114 x 10(4)L mol(-1)cm(-1) and 5.29 x 10(-3)microg cm(-2) at 400 nm, respectively. Hence, a detailed study of the extraction of nickel(II) with ECCT has been undertaken with a view to developing a rapid and sensitive extractive spectrophotometric method for the determination of nickel(II) when present alone or in the presence of diverse ions which are usually associated with nickel(II) in environmental matrices like soil and industrial effluents. Various standard alloy samples (CM 247 LC, IN 718, BCS 233, 266, 253 and 251) have been tested for the determination of nickel for the purpose of validation of the present method. The results of the proposed method are comparable with those from atomic absorption spectrometry and were found to be in good agreement.
镍（II）与N-乙基-3-咔唑甲醛-3-硫代半卡巴腙（ECCT）反应形成黄色络合物，该络合物在pH 6.0的醋酸钠和醋酸缓冲溶液中被萃取到正丁醇中。在400 nm处，于不同时间间隔测量镍（II）-ECCT络合物的吸光度值，以确定该络合物的时间稳定性。该络合物向溶剂中的萃取瞬间完成且在72小时以上保持稳定。该体系在镍（II）浓度为1.2 - 5.6 μg ml⁻¹范围内符合比尔定律，具有良好的线性，相关系数为0.999。在400 nm处，萃取物种的摩尔吸光系数和桑德尔灵敏度分别为1.114×10⁴ L mol⁻¹ cm⁻¹和5.29×10⁻³ μg cm⁻²。因此，对用ECCT萃取镍（II）进行了详细研究，旨在开发一种快速、灵敏的萃取分光光度法，用于单独测定镍（II）或在存在通常与土壤和工业废水等环境基质中的镍（II）相关的多种离子时测定镍（II）。为验证本方法，对各种标准合金样品（CM 247 LC、IN 718、BCS 233、266、253和251）进行了镍测定测试。所提出方法的结果与原子吸收光谱法的结果相当，且发现两者吻合良好。
