基于流动注射分析与分光光度法测定制革废水中微量Cr(Ⅵ)

Flow injection spectrophotometric determination of trace Cr(Ⅵ) in tanning wastewater

研究在1.0 mol/L的 H2SO4溶液中,基于Cr（Ⅵ）与二苯基碳酰二肼（DPC）的显色反应,建立了Cr（Ⅵ）的流动注射光度分析新方法.结果表明：在理想的测定条件下,有色溶液的最大吸收波长为540 nm,ρ（Cr（Ⅵ））在0.03～1.60 mg/L范围内符合比尔定律,检测限为0.013 6 mg/L,测定频率为100次/h.11次重复测定的相对标准偏差小于4%;该方法具有选择性好、灵敏度高、分析速度快、简便易行等特点.

In 1.0 mol/LH2SO4 solution a rapid and simple flow-injection spectrophotometric method has been developed for Cr(Ⅵ) determination,based on the violet-red Cr(Ⅵ)-diphenylcarbazone chelates formed by reactions. The results show,under optimized conditions, the maximum absorption of the complex is at 540 nm and the detection limits of the method is 0.0136 mg/L for Cr(Ⅵ) and Beer's law is obeyed for Cr(Ⅵ) in the range of 0.03～1.60 mg/L. The determination frequency is 100/h. The relative standard deviation of eleven replicates is less than 4.0%. The remarkable characteristics of this method are better selectivity, higher sensitivity, higher analytical speed and simpler operation.