Discussion on analyses related to peroxide initiators
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Recently, peroxide-based initiators have been analyzed, with tert-butyl benzoate peroxide serving as the reference standard. Regarding the analysis of the content of the main component and that of tert-butyl hydroperoxide, the following questions arise: When analyzing tert-butyl hydroperoxide, ceric sulfate is used for oxidative titration; why then does ceric sulfate not react with the main peroxide-based initiator?
This post was last edited by qugd on 2021-11-2 at 08:58. I believe your measurement method involves back-titration; that is, an excess amount of an inorganic reducing agent standard solution is added, and after reacting with tert-butyl perbenzoate, the remaining amount of this inorganic reducing agent is then titrated using a standard cerium solution. In normal aqueous systems, cerium(IV) ions react first with easily reducible inorganic reductants; therefore, the potential value at the endpoint should be relatively low. Once the endpoint indicator has changed color to indicate the endpoint, even a slight excess of cerium(IV) ions (one or two drops) will not cause the organic substances in the solution to be oxidized, resulting in any titration error. If potentiometric method is used to indicate the endpoint, better control may be achieved. In general aqueous solutions, the carbon atoms of oxidized organic compounds are converted into inorganic carbon dioxide, which requires a stronger oxidizing agent or a higher acidity – similar to the persulfates used in the determination of organic carbon, or the high-concentration sulfuric acid medium conditions used in COD testing.