自动电位滴定法测定水中总硬度方法的研究

目的:建立自动电位滴定仪在线滴定水中总硬度的检测方法。方法:确立本检测方法的条件及测定模式的方法学试验。结果:选用DET电位滴定模式,若取50ml水样,本方法最低检测质量浓度为1 00mg/L,回收率为95 .0% ~104%,相对标准偏差RSD为0. 88% ~11. 9%,自动电位滴定法(仪器法)与国家标准方法(容量法)对比测定结果(n=28),采用配对t检验进行分析,仪器法与容量法测定的结果无显著性差异(P>0 .50)。实际样品测定,结果满意。结论:自动电位仪在线滴定法配有直观的屏幕、实时显示滴定曲线;能够自动控制滴定过程、判断终点、处理数据;具有快速、简单的特点;结果准确可靠,重现性好,适用于检测水中总硬度的含量。

On-line determination of hardness in drinking wanter by potentiometer

Objective:To establish a method for on-line determination of hardness in drinking water.Methods:Some experimental conditions and the type of the method were found through test.Results:Dynamic equivalence point titration was used in this method, the lowest detection concentration was 1.00 mg/L if 50 ml sample was taken, the recovery was 95.0%~104.0%, and the relative standard deviation (RSD) was 0.88%~11.9%.Through partnership t test ( n =28), it was concluded that there were no significant difference ( P >0.50) between on-line titroprocessor method (equipment method) and national standard method (capacity method).By detecting real samples, the result was satisfied.Conclusion:On-line titroprocessor with screen can directly show titration curve, automatically control titration process, judge titration end point and treat data; The method is fast, simple, accurate, precise and suitable for determination of dardness in drinking water.