title: Determination of chromium (III) using a homogenous mixture of water-ethanol-methylisobutylketone solvents.
abstract: The use of organic solvents to increase metal ion determination sensitivity by atomic absorption spectrophotometry with flame is quite common. The most employed organic solvent is 4-methyl-2-pentanona (methylisobutylketone, MIBK) which optimizes sample vaporization and combustion. In this work, we present the use of a homogeneous mixture of water-ethanol-MIBK solvents (1:14:10 v/v, respectively), named the single-phase solution instead of employing pure organic solvents to determine chromium (III) ions by atomic absorption spectrophotometry with flame. The analytical calibration curve in single-phase solution evaluated up to 8 mugml(-1) was linear and was described as Abs=0.0048 C(Cr(III))-0.0010 (r(2)=0.9998). Stability in the measurement as well as an increase in sensitivity more than twice as high when compared to determinations exclusively made in aqueous solutions were observed. The exactness of the determinations was evaluated with the same steel standards.
authors.affiliation: Instituto de Quimica, Universidade Federal de Uberlândia, Caixa Postal 593 38400-902 Uberlândia, MG, Brazil.
authors.forename: Sebastião de Paula
authors.initials: Sde P
authors.lastname: Eiras
authors.forename: Uenes Martins
authors.initials: UM
authors.lastname: Custódio
authors.forename: Luiz Alfredo
authors.initials: LA
authors.lastname: Pavanin