酒石酸钠标定法测定二氧化硫产品微量水分

Determination of Trace Moisture in Sulfur Dioxide Products by Sodium Tartrate Calibration Method

针对GB/T 6283-2008中采用酒石酸钠法测定产品中微量水分时,仅标明酒石酸钠的纯度要求给测定结果的准确性带来不确定的问题,进行了酒石酸钠保存条件、稳定性、失水温度和含水率方面的实验,建立了测定酒石酸钠含水率后标定卡尔·费休试剂滴定度来测定产品中微量水分的方法。结果表明,酒石酸钠在115~130℃条件下失水率趋于稳定,可以认为其完全失去结晶水。该方法可以有效降低由酒石酸钠含水率变化带来的测量误差,降低测量误差的幅度可达15%以上。

In GB/T 6283-2008, when sodium tartrate was used to determine trace water in products, the purity requirement of sodium tartrate was only indicated, which brought uncertainty to the accuracy of the determination results. The preservation conditions,stability, dehydration temperature and moisture content of sodium tartrate were tested. A method for determining trace water in products was established by calibrating Karl Fischer reagent titration after determining the moisture content of sodium tartrate. The results showed that the dehydration rate of sodium tartrate tended to be stable at 115~130 ℃, which can be considered to completely lose crystal water. This method can effectively reduce the measurement error caused by the change of water content of sodium tartrate, and the reduction of measurement error can reach more than 15%.