Detection of carbonates in sodium hydrosulfide
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We generally conduct tests in accordance with national standards. However, analysis shows that the coexistence of sodium carbonate and sodium bicarbonate results in inaccurate test data. Has anyone tested this using ion chromatography?
Hehe! I’m paying attention; if anyone knows, please reply. Let us newcomers learn about it as well.
Ion chromatography cannot separate carbonate and bicarbonate; at certain pH values, their retention times may change, but the chromatographic peak that appears is one. If an acid contains several ionizable hydrogen ions, then there will be as many chromatographic peaks; phosphoric acid, for example, produces three peaks. Some organic polyacids yield a series of chromatographic peaks, which leads to great analytical complexity. Regardless of whether it is a polyprotic acid or not, under the analysis conditions of ion chromatography, an acid appears as only one component peak.
If the poster wants to detect carbonates in sodium sulfide, it can be done by converting the carbonates into insoluble calcium or barium salts as precipitates; that is, calcium chloride or barium chloride is used to cause the carbonate ions to form precipitates and thus be separated from sodium sulfide. The concentration of carbonate ions can then be determined through complexometric titration or neutralization titration. If the purity of caustic sulfide is to be determined, the sulfur ion content can be measured by potentiometric titration and then converted into the content of caustic sulfide.