title: Formation of a liquid organic ion associate in aqueous solution and its application to the GF-AAS determination of trace cadmium in environmental water as a complex with 2-(5-bromo-2-pyridylazo)-5-(N-propyl-N-sulfopropylamino)phenol.
abstract: The formation of a liquid organic ion associate in an aqueous sample was applied to the concentration and determination of cadmium in environmental water samples. Cadmium was converted into a complex with 2-(5-bromo-2-pyridylazo)-5-(N-propyl-N-sulfopropylamino)phenol (5-Br-PAPS) in a 40-mL sample solution, and was extracted into a liquid ion associate of phenolsulfonate and benzethonium during phase formation. More than 400-fold enrichment was easily attained by this technique, because the volume of the liquid organic phase formed was very small, ca. 2 microL. After dilution of the organic phase with a small volume of 2-methoxyethanol, the cadmium in the solution was determined by GF-AAS. The detection limit was 0.09 ng/L (3sigma(b)). This method was applied to the determination of cadmium in river water and seawater.
authors.affiliation: Graduate School of Science and Engineering (Science Div), University of Toyama, Toyama, Japan. noriko@sci.u-toyama.ac.jp
authors.forename: Noriko
authors.initials: N
authors.lastname: Hata
authors.forename: Shiho
authors.initials: S
authors.lastname: Hieda
authors.forename: Mika
authors.initials: M
authors.lastname: Yamada
authors.forename: Rie
authors.initials: R
authors.lastname: Yasui
authors.forename: Hideki
authors.initials: H
authors.lastname: Kuramitz
authors.forename: Shigeru
authors.initials: S
authors.lastname: Taguchi