title: Arsenazo III as a spectrophotometric reagent for determination of lead.
abstract: Arsenazo III is proposed as a spectrophotometric reagent for the determination of lead. The complex formation begins at pH > 2 and is greatest at pH 4-6. The molar absorptivity of the complex has a mean value of 2.8 x 10(4) 1.mole(-1).cm(-1) at 600 nm and remains nearly constant in the pH range 4-8. The ionic species taking part in the reaction are studied and the equilibrium constants for the different possible reactions are calculated. According to the values obtained, the reaction of PbOH(+) with H(5)L(3-) is predominant. The reaction studied is applied for the determination of micro amounts of lead in technical aluminium.
authors.affiliation: Department of Chemistry, University of Sofia, 1126 Sofia, Bulgaria.
authors.forename: V
authors.initials: V
authors.lastname: Michaylova
authors.forename: N
authors.initials: N
authors.lastname: Kuleva