title: Improved spectrophotometric determination of osmium(VIII) with 4-(2-pyridylazo) resorcinol in mixed surfactants.
abstract: The colour development between 4-(2-pyridylazo)-resorcinol(PAR) and osmium(VIII) in the presence of cationic and nonionic surfactants in a weakly acidic medium was more stable and reproducible than in the absence of surfactant (PAR-alone method). An improved spectrophotometric determination of osmium(VIII) with PAR was investigated in the presence of mixed surfactants of N-hexadecyltrimethylammonium chloride (HTAC) and Brij 58 [poly(oxyethylene)lauryl ether] as cationic and nonionic surfactants at pH 6.0-7.2. The calibration graph was linear in the range 0-110 microg/10 ml osmium(VIII), and the apparent molar absorptivity was 2.4 x 10(4) l.mole(-1).cm(-1) with a Sandell sensitivity of 0.0079 microg/cm(2) osmium(VIII).
authors.affiliation: Osaka University of Pharmaceutical Sciences, 2-10-65 Kawai, Matsubara-city, Osaka, Japan.
authors.forename: I
authors.initials: I
authors.lastname: Mori
authors.forename: Y
authors.initials: Y
authors.lastname: Fujita
authors.forename: M
authors.initials: M
authors.lastname: Toyoda
authors.forename: Y
authors.initials: Y
authors.lastname: Hasegawa