title: Cloud point extraction for the determination of As(III) in water samples by electrothermal atomic absorption spectrometry.
abstract: Cloud point extraction was applied as a preconcentration step for electrothermal atomic absorption spectrometry (ETAAS) determination of As(III) in aqueous solutions. After complexation with ammonium pyrrolidinedithiocarbamate, the analyte was quantitatively extracted to the surfactant-rich phase in the non-ionic surfactant octylphenoxypolyethoxyethanol (Triton X-114) after centrifugation. 0.1molL(-1) HNO(3) in methanol was added to the surfactant-rich phase before ETAAS determination. The precision (R.S.D.) for 11 replicate determinations of 5.0mugL(-1) of As(III) was 3.0%. The concentration factor, which is defined as the concentration ratio of the analyte in the final diluted surfactant-rich extract ready for ETAAS determination and in the initial solution, was 36 for As(III). The linear concentration range was from 0.1 to 20mugL(-1). The developed method was applied to the determination of As(III) in lake water and river water.
authors.affiliation: State Key Laboratory of Functional Polymer Materials for Adsorption and Separation, and Research Center for Analytical Sciences, College of Chemistry, Nankai University, Tianjin 300071, China.
authors.forename: An-Na
authors.initials: AN
authors.lastname: Tang
authors.forename: Guo-Sheng
authors.initials: GS
authors.lastname: Ding
authors.forename: Xiu-Ping
authors.initials: XP
authors.lastname: Yan