Potentiometric determination of pK(a) values of 1,4,5,8-tetrahydroxy-9-oxo-10-pentyl-9,10-dihydro-acridine-2,3,6,7-tetracarboxylic acid (TPAT) extracted from Laurus nobilis

Ibaoglu K., Sari H. I., Tuzen M., Mendil D., Soylak M.

CHEMIA ANALITYCZNA, vol.49, no.5, pp.635-642, 2004 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 49 Issue: 5
  • Publication Date: 2004
  • Journal Name: CHEMIA ANALITYCZNA
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.635-642
  • Erciyes University Affiliated: Yes

Abstract

The pK(a), values of 1,4,5,8-tetrahydroxy-9-oxo-10-pentyl-9,10-dihydro-acridine-2,3,6,7- tetracarboxylic acid (TPAT) extracted from Laurus nobilis were determined by Molspin potentiometric titration at 25degreesC in the presence of 0.1 mol dm(-3) NaCl. The pK(a) values were calculated using SUPERQUAD computer program. Initially deprotonation occurs in carboxylic groups, then at the nitrogen atom of the alkyl group, and finally at the hydroxylic groups of TPAT. The following pK(a) values were computed: 2.65, 3.36, 4.08, 5.43, 6.84, 9.30, 10.42 and 10.53.