title: Purification of xylenol orange by preparative paper chromatography, and examination of its zirconium complex.
abstract: Preparative paper chromatography is proposed as a suitable method for purification of Xylenol Orange (XO). The last three dissociation constants of pure XO have been determined with the aid of the program SPEKTFOT, the values found being pK(9) = 12.34; pK(8) = 10.66; pK(7) = 6.69 (0.1M KNO(3), 20 +/- 0.5 degrees ). The complexation of zirconium with the purified reagent has been studied and the co-existence of ML and M(2) L complexes proved by use of the program DALSFEK. The following conditional stability constants of the complexes and their molar absorptivities were computed: log beta'(ml) 4.58; log beta'(M(2)L) 11.59; (ML) 2.00 x 10(4); (M(2)L) 9.40x 10(4) l.mole(-1).cm(-1) at 550 nm.
authors.affiliation: Department of Analytical Chemistry, University of Sofia, 1126 Sofia, Bulgaria.
authors.forename: V
authors.initials: V
authors.lastname: Michaylova
authors.forename: L
authors.initials: L
authors.lastname: Sůcha
authors.forename: M
authors.initials: M
authors.lastname: Suchánek