罗丹明B荧光猝灭法测定痕量Cr(VI)的研究

Determination of Cr(VI) by fluorescence quenching method

基于六价铬与碘化钾反应生成了单质碘,碘可以使罗丹明B发生荧光猝灭,从而间接测定六价铬的含量.六价铬浓度在0.01-0.5μg/mL范围内,荧光强度差值与六价铬浓度呈线形关系,线性回归方程为△F=121.58CCr(VI)(μg/mL)+16.17,相关系数r=0.9990,检测限为2.4ng/mL.该方法简便,快速,灵敏度高,已用于环境样品中六价铬的测定,回收率在99.8%-104.2%,结果满意.

A simple and sensitive fluorescence quenching method for determination of Cr（VI） is investigated. The method is based on fluorescence quenching of Rhodamine B by reaction of Cr（VI） with potassium iodide giving iodine（I2）. The calibration graph is linear over the range 0.01-0.5μg/mL Cr（VI）. The linear equation is △F=121.58CCr（VI）（μg/mL）＋16.17, and the relative coefficient is 0.9990. The detection limit is 2.4ng/mL. The method has been applied successfully to the determination of Cr（VI） in environmental water. The recovery of this method for detecting Cr（VI） is 99.8%-104.2% and the result is satisfactory.