镀锌层中Cr6+的测定

研究用光度法测定镀锌层中六价铬的方法,建立了最佳工作条件,进行了干扰试验。结果表明,最大吸收波长位于540 nm处,显色酸度控制在pH=2±0.5,以pH=2时显色最好;当显色剂用量>1.5 mL时,吸光度最大且恒定;浸取温度选择在70℃时,吸光度稳定且最大;吸光度测定选择浸取时间以1 h为宜。Cr6+在0~40μg内符合比尔定律,线性相关系数r=0.999 8。

Determination of Cr+6 in Galvanized Coat

To study the method of determining the Cr+6in galvanized coat by spectrophotometry,and the optimum workingconditions are established,the interference experiments are done.The results show that the maximum absorbing wavelength lies to 540 nm;the development acidity is controlled at pH=2±0.5,the development is the optimum at pH=2;when the dosage of developer is more than 1.5 mL,the absorbance is maximum and constant;when the leaching tempera-ture is selected at 70℃,the absorbance is stable and maximum;selecting 1 hour leaching time is suitable for absorbancedetermination.The Cr+6accord with Lambert-Beer’s law in the scope of 0 ~40 microgramme,the linear relativity coeffi-cient equals 0.999 8.