Issue 48/2015 - Ion chromatography enables rapid determination of chlorate and sulfate in refined brine in the chlor-alkali industry

Thermo Fisher recently released a detection protocol
for chlorate and sulfate in refined brine water.
The presence of chlorate and sulfate in brine is extremely harmful to the production of diaphragms and ion membranes, and excessive sulfate content is easy to form precipitation with alkaline earth metals and cause membrane blockage and damage, so the concentration
of chlorate and sulfate must be monitored.

The classical determination methods of sulfate mainly include gravimetric method and volumetric method, among which gravimetric method has a long analysis time, cumbersome operation, and high
requirements for the operator's experimental skills.
The volumetric method is also complicated to operate, and the color change of the color developer at the end point of titration is difficult to judge, which affects the accuracy
of the measurement.
Thermo Fisher Fisher Scientific has released a protocol for the detection of chlorate and sulfate in refined brine that focuses on the use of simple ion chromatography in this field, which can easily and quickly determine the content
of chlorate and sulfate in refined brine .

This method mainly uses Thermo ScientificTM DionexTM ICS-1100 basic integrated ion chromatograph, and establishes a set of ion chromatography method for the determination of chlorate and sulfate in refined brine in chlor-alkali industry, which is separated by high-capacity anion exchange column IonPac AS22 and suppressed by suppressor and then detected by conductivity detector, and the high concentration of chloride ion matrix in brine does not affect the analysis of
these two ions to be measured 。 This method is easy to operate, has good selectivity and higher sensitivity, and can complete an analysis within 13 minutes, so as to realize the real-time monitoring of chlorate and sulfate in raw material brine, process refined brine and final products in the chlor-alkali industry, and ensure the normal operation
of chlor-alkali production.
(Shao Shuai)