title: Spectrophotometric determination of gadolinium(III) with 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol (5-Br-PADAP).
abstract: Reaction between gadolinium(III) and 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol (5- Br-PADAP) was studied for delineating optimal conditions for complexation. This reagent can be used for the spectrophotometric determination of Gd(III) in concentrations ranging from 0.04 to 1.2 ppm (a = 1.76(+/- 0.03) x 10(5) (1.(-1) mole(-1). cm). The reaction takes place at a pH between 9.2 and 11.6. In the presence of Triton X-100 this complex is soluble in water. In order to overcome difficulties caused by the presence of other lanthanides, an ion exchange chromatographic technique was used.
authors.affiliation: Department of Analytical Chemistry, Faculty of Chemistry, Biochemistry and Pharmacy, National University of San Luis, P.O. Box 375, 5700-San Luis, Argentina.
authors.forename: L D
authors.initials: LD
authors.lastname: Martinez
authors.forename: E
authors.initials: E
authors.lastname: Perino
authors.forename: E J
authors.initials: EJ
authors.lastname: Marchevsky
authors.forename: R A
authors.initials: RA
authors.lastname: Olsina