【摘要】 基于六价铬与碘化钾反应生成了单质碘 ,碘可以使 2′ ,7′ 二氯荧光素 (DCF)发生荧光猝灭 ,从而间接测定六价铬。六价铬浓度在 0 .2 0～ 2 .5 0 μg/2 5ml范围内 ,荧光强度差值与六价铬浓度呈线性关系 ,线性回归方程ΔF =12 .12C + 0 .19,相关系数r =0 .9993,检出限为 0 .10 μg/2 5ml。方法简便、灵敏度较高 ,已用于合成样中六价铬的测定 ,回收率在 10 0 %～ 10 3% ,结果满意更多还原

【Abstract】 A simple and sensitive fluorescence quenching method for the determination of Cr(Ⅵ) was investigated. The method is based on the reaction of Cr(Ⅵ) with potassium iodide giving iodine (I 2), which is estimated by its fluorescence quenching effect on the fluorescence reagent 2′7′ dichlorofluorescein (DCF). The calibration graph is linear over the range 0.20～2.50μg per 25ml Cr(Ⅵ). The linear regression equation is Δ F=12.12C +0.19 and the relative coefficient is 0.9993. The detection limit is 0.10μg per 25ml Cr(Ⅵ). The method has been applied successfully to the determination of Cr(Ⅵ) in simulated mixtures. The recovery of this method for detecting Cr(Ⅵ) is 100%～103%.更多还原