流动注射-分光光度法测定水中的痕量Cr(Ⅲ)和Cr(Ⅵ)

Flow injection-spectrophotometric determination of trace Cr(Ⅵ) and Cr(Ⅲ) in water

建立了测定水中痕量 Cr( )和 Cr( )的二苯基碳酰二肼 ( DPC) -流动注射分光光度法。将含 Cr( )和 Cr( )的水样及用 KMn O4 氧化后的水样 ,分别注入到 H2 SO4 溶液和 DPC溶液的混合流中 ,在λmax=5 4 0 nm处对反应形成紫红色螯合物用分光光度测定 Cr( )和 Cr( )。线性范围为 0 .0 3～ 1 .80mg/L,检出限为 0 .0 1 4mg/L,测定频率为 1 0 0次 /h。可用于测定工业废水中Cr( )和 Cr( )

Diphenyl carbazide(DPC)FIAspectrophotometric determination of trace Cr(Ⅳ) and Cr(Ⅲ) in water was studied. The water sample containing Cr(Ⅵ) and Cr(Ⅲ) was injected into the mixed flow of H2SO4 and DPC solutions, so did the water sample which was oxidized by KMnO4 . The chelate formed by the reaction was spectrophotometrically detected at λ max =540 nm. The linear range is 003 to 180 mg/L with detection limit of 0014 mg/L and the determination frequency is 100 times per hour. It was applied to determination of trace Cr(Ⅳ) and Cr(Ⅲ) in waste water.