滴定法测定水中碳酸根、重碳酸根和氢氧根的质量控制探究

Study on Quality Control of Titration for Determination of Carbonate,Bicarbonate and Hydroxide in Water

水中碳酸根、重碳酸根和氢氧根的测定已成为测定水质情况的常见指标之一。在其他指标检测时均可直接采用含有一定量目标成分的物质作为质量控制的样品,但是由于三者在水中会发生反应,导致无法同时存在于水中,所以在测定三种成分时选取的质量控制样品成为了一个难点。本文选取总碱度作为质量控制的样品,其碳酸根检出限为6 mg/L,重碳酸根检出限为3.05 mg/L,氢氧根检出限为0.85 mg/L,精密度为2.60%,标准物质的测试结果均在不确定度范围内,证明此操作可行,有效。

The determination of carbonate,bicarbonate and hydroxide in water has become one of the common indexes for measuring water quality.In the detection of other indicators,substances containing a certain amount of target components can be directly used as quality control samples.However,due to the reaction of the three components in water,they cannot exist in water at the same time,so the quality control samples selected in the determination of the three components become a difficult point.In this paper,the total alkalinity is selected as the sample for quality control,and the detection limits of carbonate,bicarbonate and hydroxide are 6 mg/L,3.05 mg/L and 0.85 mg/L,respectively,with a precision of 2.60%.The test results of standard materials are within the uncertainty range,which proves that this operation is feasible and effective.