高精度散射光度滴定法测定Cl-的含量

目的用检测溶液浑浊程度来指示Ag+滴定Cl-的滴定终点, 测定Cl-的含量.方法将一束光线通入待测溶液中, 在溶液中与其垂直的方向上检测散射光相对强度, 随着AgNO3溶液的加入, 溶液将逐渐变得浑浊, 散射光相对强度逐渐增强, 如果沉淀反应完全, 散射光相对强度将在化学计量点处达最大值, 由此可判断滴定终点(称散射光度滴定法).结果该滴定方法较荧光黄和铬酸钾指示剂法适用于更低浓度的Cl-含量检测, 在适当的条件下该方法的精密度和准确度均可小于千分之二.结论散射光度滴定方法可用于测定较低浓度的Cl-的含量.

To Determine to Concetration of Cl- with Highli-accurate Nephelometric Titrimetry

Objective To introduce a new method for indicating the titration end point of Cl - with Ag + by the measurement of the relative intensity of scattered light in the titrate solution. Methods Light on the detectors creates a current flow through the diodes. With the addition of the AgNO 3 solution, the titrate solution will be turbid and the intensity of the scattered light in the solution will increase gradually and reach the maximum at the stoichiometric point; thus the titration end point can be indicated. Results The new method is appropriate for the solution with lower concentration of Cl -, compared with the fluorescein and potassium chromate indicator method. Its accuracy and precision are better than two thousandths under suitable conditions. Conclusion The new method can be used to indicate the titration end point of Cl - with Ag +.