title: Kinetic determination of ultramicro amounts of copper.
abstract: A new catalytic reaction is proposed and a kinetic method developed for the determination of ultramicro amounts of Cu(II) on the basis of its catalytic activity in oxidation of the 2-thiosemicarbazone of sodium 1,2-naphthoquinone-4-sulphonate by hydrogen peroxide in the presence of ascorbic acid. Under optimal conditions the sensitivity of the method is 0.25 ng/ml. The relative error is 4.8-18.2% for the concentration range 5-0.8 ng/ml. Most foreign ions do not change the rate of the catalysed reaction. Co(2+) and I(-) catalyse the reaction, Ni(2+) extensively inhibits it, and in the presence of EDTA only the uncatalysed reaction takes place.
authors.affiliation: Faculty of Science, University of Pristina, 38000 Pristina, Yugoslavia.
authors.forename: R P
authors.initials: RP
authors.lastname: Igov
authors.forename: M D
authors.initials: MD
authors.lastname: Jaredić
authors.forename: T G
authors.initials: TG
authors.lastname: Pecev