title: Online determination of copper in aluminum alloy by microchip solvent extraction using isotope dilution ICP-MS method.
abstract: Isotope dilution mass spectroscopy (IDMS)/ICP-MS combined with microchip solvent extraction was successfully applied for the online determination of copper in an aluminum alloy. The microchip solvent extraction was developed for the separation of Cu from major element, and optimal pH range was wider than that of the batchwise extraction method. The dimensions of the microchip were 30 mm x 70 mm and that of micro-channel on the microchip was 180 microm wide and 40 microm deep. The copper complex with 8-hydroxyquinoline was extracted into o-xylene at pH 5.5 and back extracted with 0.1 mol l(-1) nitric acid at flow rate of 20 microl min(-1). The total extraction efficiency (water/organic solvent/nitric acid) was around 40%. IDMS/ICP-MS was coupled with solvent extraction for precise determination of Cu. The extraction and back-extraction on the microchip took about 1s and the total measurement time for the IDMS/ICP-MS was about 40s/sample. The blank value of this method was 0.1 ng g(-1). The proposed method was used for the determination of Cu in Al standard materials (JSAC 0121-C, The Japan Society for Analytical Chemistry and 7074 Al alloy, Nippon Light Metal Co. Ltd.). The obtained analytical results are in good agreement with the certified values.
authors.affiliation: Analysis Research Department, Chemical Research Laboratories, Nissan Chemical Industries, Ltd., 722-1 Tsuboi-cho, Funabashi 274-8507, Japan.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Kagawa
authors.forename: Masashi
authors.initials: M
authors.lastname: Ohno
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Seki
authors.forename: Katsumi
authors.initials: K
authors.lastname: Chikama