流动注射分光光度法快速测定水样中的铬

建立了用流动注射分光光度法快速检测水样中铬含量的方法.测定耗时140 s,测定频率25样/h.本法利用Cr(Ⅵ)和二苯碳酰二肼显色反应,Cr(Ⅵ)标准溶液的质量浓度在0.05～0.8 mm/L之间与吸光度呈线性.该法的检出限是4.0 μg/L,低于国家对Ⅰ类水的相关标准.应用此法分别测定了北京城区一些地表水中铬的含量,加标回收率在90.1%～113%之间.

Determination of hexavalent chromium in water by fast flow injection spectrophotometry

A simple and fast flow injection spectrophotometric analysis is developed for the determination of chromium in water samples. In acidic solution, a violet-red Cr(Ⅵ)-diphenylcarbazone chelate were formed by the reaction of hexa-valent chromium and diphenyl carbazide (DPC), and spectrophotometrically detected at λ_(max) 540 nm. The detec-tion limits of the method is 4.0 μg/L. The developed method was applied to the detection of Cr(Ⅵ) in water samples in Beijing. The recoveries were 90.1%～113%.