期刊论文

Cadmium Determination With the Ternary Complex of Cd^2＋-SCN^--MB System by a New Dual-wavelength Spectrophotometry

中文

中南医学科学杂志

2095-1116

2008

36

5

574-576

10.3969/j.issn.2095-1116.2008.05.002

本校为第一机构

目的建立测定水样中痕量Cd^2＋的新方法。方法在稀硫酸介质中,Cd^2＋与SCN^-形成的配合物能与亚甲蓝（MB）形成离子缔合物。以试剂空白为参比,在离子缔合物最大吸收波长550.5 nm（测定波长）处测定其吸光度A2,并以该离子缔合物为参比,在亚甲蓝最大吸收波长666 nm处（参比波长）测定试剂空白吸光度A1。结果两波长处吸光度差值（△A=A2-A1）与Cd2＋浓度在8.06×10^-3-0.250μg/mL范围内有良好线性关系,相关系数0.9981,检出限2.42 ng/mL。结论方法操作简单,结合巯基棉分离技术,应用于环境水样中Cd2＋的测定,相对偏差小于2.00%,样品加标回收率95.0%-96.8%。

Objective To propose a method for determination of trace cadmium in water sample. Methods Utilizing methylene blue（MB） associated with coordination anion formed by Cd^2＋ with SCN^-in the dilute sulfuric acid medium,the A2 of the ionic associate at 550.5 nm in comparison with the reagent blank and the A1 of the blank at 666 nm in comparison with the ionic associate,respectively,were determined. Results The absorbance difference（△A=A2-A1） was linear to the concentration of Cd^2＋ in the range of 8.06×10^-3～0.250 μg/mL with correlation co...