Abstract
A potentiometric back-titration method for the determination of sulfate ions using a plasticized poly(vinyl chloride) membrane electrode sensitive to a titrant is described. The method is based on ion association between the excess of 2-aminoperimidinium added to the sulfate ion in the sample and sodium tetrakis (4-fluorophenyl) borate (FPB) in the titrant. The titration end-point was detected as a sharp potential change due to an increase in the concentration of the free FPB at the equivalence point. The end-point was detected even in the presence of a 20-fold excess of common cations and anions relative to the concentration of the sulfate ion within ~2% of titration error. A linear relationship between the concentration of the sulfate ion and the end-point volume of the titrant exists in the sulfate ion concentration range from 2 x 10-4 to 3 x 10-3 mol l-1 using 10-2 mol l-1 FPB solutions as the titrant. The present method could be applied to determine sulfate ions in sea water.
Original language | English |
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Pages (from-to) | 669-673 |
Number of pages | 5 |
Journal | Talanta |
Volume | 48 |
Issue number | 3 |
DOIs | |
Publication status | Published - 1999 Mar |
Externally published | Yes |
Keywords
- 2-Aminoperimidinium bromide
- Plasticized poly (vinyl chloride) membrane
- Potentiometric back-titration
- Sea water
- Sodium tetrakis (4-fluorophenyl) borate
- Sulfate ion
ASJC Scopus subject areas
- Analytical Chemistry