紫外分光光度法测定水中铬(Ⅵ)的方法研究

Determination of Chromium (Ⅵ) in Water by Ultraviolet Spectrophotometry

以在酸性条件下二苯碳酰二肼(DPCI)与六价铬反应生成紫红色配合物的显色反应作为指示反应,采用紫外分光光度法直接测定水中的微量铬(Ⅵ)含量。研究了分光光度法测定水中铬的最佳条件。结果表明,溶液的最大吸收波长为540nm,线性范围在5.2×10-3～1.2×10-1mg·L-1,符合比尔定律。此方法反应灵敏,操作简单,专一性强,适用于天然水和工业废水中铬(Ⅵ)的测定。

Chromium （VI） in water was detected by the UV spectrophotometric method which based on the color reaction of Cr （Ⅵ） with diphenylcarbazide hydrazine to form purple complexes in acidic conditions. The optimized conditions were also studied. The maximum absorption wavelength at 540 nm and the linear range in 5.2×10^-3 mg·L^-1-1.2×10^-1 mg·L^-1 which was in accordance with the Beer＇s law were observed. The results showed that the UV spectrophotometric method was sensitive, simplified and specific and suit for determination of Cr（VI） in natural and waste water.