Potentiometric back-titration of sulfate ion using a tetraphenylborate derivative as a titrant and a titrant-sensitive plasticized poly(vinyl chloride) membrane electrode

Takashi Masadome, Yasukazu Asano

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A potentiometric back-titration method for the determination of sulfate ions using a plasticized poly(vinyl chloride) membrane electrode without added ion-exchanger is described. A solution of a derivative of tetraphenylborate is used as titrant. The method is based on the ion association between an excess of 2-aminoperimidinium added to the sulfate containing sample and the tetraphenylborate derivative in the titrant. The titration end-point is detected as a sharp potential change due to an increase in the concentration of the free tetraphenylborate derivative at the equivalence point. The sharpness of the titration curve at the end-point is compared for two tetraphenylborate derivatives. Good results are obtained with a solution of sodium tetrakis (4-fluorophenyl) borate.

Original languageEnglish
Pages (from-to)423-425
Number of pages3
JournalFresenius' Journal of Analytical Chemistry
Issue number4
Publication statusPublished - 1998 Jan 1


ASJC Scopus subject areas

  • Biochemistry

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