阻抑二甲基黄褪色光度法测定痕量铬(Ⅵ)  

PHOTOMETRIC DETERMINATION OF CHROMIUM(Ⅵ) BY ITS INHIBITION OF COLOR-FADING OF DIMETHYL YELLOW

作　　者：韩长秀[1] 吕庆淮[1] 

机构地区：[1]临沂师范学院化学与环境科学系,临沂276005

出　　处：《理化检验（化学分册）》2004年第12期721-722,共2页Physical Testing and Chemical Analysis(Part B:Chemical Analysis)

摘　　要：在硝酸介质中,二甲基黄显色后在加热条件下褪色,铬(Ⅵ)能显著阻抑此褪色反应。据此建立了测定痕量铬(Ⅵ)的方法。方法的检出限为1.55×10-10g·ml-1,线性范围为0.1～1 2μg/10ml,用于湖水和河水中铬(Ⅵ)含量的测定,结果满意。The color of dimethy yellow (DMY) in dilute HNO_3 solution of 0.24mol·L^(-1) tends to fade gradually when heated in a water bath of 85℃, and the color-fading is inhibited by the presence of Cr(Ⅵ). When the absorbance is measured at 515nm (λ_(max) of DMY) after heating for 270s, the magnitude of the decrease in absorbance keeps a linear relationship with the concentration of Cr(Ⅵ) in the range of 0.1～1.2μg per 10ml of solution. Detection limit of this new method is 1.55×10^(-10)g·ml^(-1). This method has been applied satisfactorily to the analysis of lake water and river water.

关 键 词：光度法 阻抑 二甲基黄 铬(Ⅵ) 湖水 河水 

分 类 号：O657.3[理学—分析化学]