How to eliminate the interference of sulfite, sulfide and carbonate in the determination of sodium thiosulfate in desulfurization solution by iodometry?

The analysis of complex component samples is the most important test of professional level. Those who are basic like me often care about one thing and lose the other. For the problems that need to be solved, we can only check more information to see if there is anything we can learn from. So I think it is also possible for you to give a reference standard. Of course, it is difficult to say whether different detection subjects are applicable. It can be used for reference.

GB/T 10500-2009 Industrial Sodium Sulfide has the analytical method you need. You can refer to it yourself, which may be helpful.

Because these components all have low sulfides, as a non selective redox titration method, it can not eliminate interference very well. Iodometry is carried out under the condition of weak acid, and there is no interference of carbonate during titration. The building owner can carefully check the redox potential value of these sulfur oxyacid radicals, and whether the content of these components can be analyzed by potential indicator redox stepwise titration. The best solution is to use ion chromatography and select appropriate separation conditions, so that the oxyacid radical of these sulfur can be determined separately. However, sulfur ions (sulfides) cannot be analyzed in a single ion chromatography, so additional analysis steps or other analysis methods are required.

Whether it is possible to add zinc acetate and filter. Eliminate sulfur interference? I think carbonate should not interfere with the determination of iodometry, and there is no plan to eliminate the interference of sulfite. See if any friends can come up with good answers.