Method for quantifying thionic acid contained in metal sulfate compound

摘要

PROBLEM TO BE SOLVED: To accurately quantify at least one of thiosulfate ions and sulfite ions included in a metal sulfate compound.SOLUTION: The method for quantifying thionic acid is provided that is adapted to quantify both or one of thiosulfate ions or sulfite ions as thionic acid included in a metal sulfate compound. The method comprises: a preparation step of preparing a sample solution including a metal sulfate compound to be measured and a solvent; a derivatization step of forming a thiosulfuric acid derivative and a sulfurous acid derivative by adding a derivatization agent to the sample solution to react it with thiosulfate ions and sulfite ions derived from the metal sulfate compound; a separation step of separating the thiosulfuric acid derivative and the sulfurous acid derivative for each type by extracting a solid phase from the sample solution using a solid phase column showing different adsorption performances corresponding to the types of the derivatives; and a measurement step of quantifying both or one of the thiosulfate ions or the sulfite ions from the separated thiosulfuric acid and sulfurous acid derivatives.SELECTED DRAWING: Figure 1