Periodatometric determination of organotrithiocarbonates and mercaptans (via trithiocarbonate formation)

A method has been described for the direct visual and potentiometric determination of organotrithiocarbonates in bicarbonate medium in the presence of potassium iodide, using potassium periodate as an oxidimetric reagent. The method was extended to the determination of mercaptans after their quantitative transformation to the corresponding organotrithiocarbonates through reaction with carbon disulfide in the presence of alkali. The resulting trithiocarbonates are titrated with periodate in the manner described herein. The excess of carbon disulfide does not interfere in these determinations. Organotrithiocarbonates are smoothly, rapidly, and quantitatively oxidized to the corresponding bis(alkyl/aryl mercapto thiocarbonyl) disulfides with the oxidant under the specified conditions.