title: Preconcentration of 1-(2-pyridylazo)-2-naphthol-iron(III)-capriquat on a membrane filter, and third-derivative spectrophotometric determination of iron(III).
abstract: Iron(III) was preconcentrated by collection on an organic solvent-soluble membrane filter (nitrocellulose (NC)) of the iron(III)-1-(2-pyridylazo)-2-naphthol (PAN) complex in the presence of capriquat as an oily quaternary ammonium salt. Third-derivative spectrophotometry was used for measurement of the third-derivative distance (d(3)A/dlambda(3)) between lambda(1) = 520 nm and lambda(2) = 590 nm or lambda(3) = 660 nm and lambda(4) = 724 nm of the iron(III)-PAN-capriquat complex or PAN-capriquat in dimethylsulfoxide (DMSO) following preconcentration. The calibration curve was linear in the range of 1-10 mug iron(III)/5.0 ml DMSO solution. The proposed method was about five-fold more sensitive and more selective than using zero-order spectrophotometry.
authors.affiliation: Osaka University of Pharmaceutical Sciences, Matsubara-shi, Osaka 580, Japan.
authors.forename: I
authors.initials: I
authors.lastname: Mori
authors.forename: M
authors.initials: M
authors.lastname: Toyoda
authors.forename: Y
authors.initials: Y
authors.lastname: Fujita
authors.forename: T
authors.initials: T
authors.lastname: Matsuo
authors.forename: K
authors.initials: K
authors.lastname: Taguchi