[中文文摘]本文研究了用荧光猝灭法测定痕量六价铬。本方法是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0.20-2.50μAg/25ml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△F=12.12C+0.19,相关系数γ=0.9993,检测限为0.1μg/25mL。本法简便、灵敏度高,已用于合成样中六价铬的测定,回收率在100～103％,结果令人满意。[英文文摘]A simple and sensitive fluorescence quenching method for the determination of Cr (Ⅵ) has been investigated. The method is based on the reaction of Cr (Ⅵ) with potassium iodide giving iodine (I_2), which is estimated by the fluorescence quenching method using 2'7'- dichlorofluorescein (DCF). The calibration graph is linear over the range 0. 20-2. 50μg per 25mL Cr (Ⅵ). The linear regression eqnation is △F=12.12c+0.19 and the velative coeffi- cientr is 0.9993. The detection limit is 0. 10μg per 25ml Cr (Ⅵ). The method has applied successfully to the determination of Cr(VI) in synthetic mixtures.The recovery are 100-103%
