title: Selective and sensitive speciation analysis of Cr(VI) and Cr(III) in water samples by fiber optic-linear array detection spectrophotometry after ion pair based-surfactant assisted dispersive liquid-liquid microextraction.
abstract: A simple ion pair based-surfactant assisted dispersive liquid-liquid microextraction (IP-SA-DLLME) was evaluated for extraction and preconcentration of Cr(VI) and Cr(III) in aqueous samples. In this method, which was used for the first time for chromium speciation analysis, sodium dodecyl sulfate (SDS) was used as both ion-pairing and disperser agent. Cr(VI) ions were converted into their cationic complex with 1,5-diphenylcarbazide (DPC) and then extracted into 1-octanol dispersed in aqueous solution. Cr(III) ion also can be determined by this procedure after oxidation to Cr(VI). After extraction and phase separation, upper organic phase was transferred to a micro cell of a fiber optic-linear array detection spectrophotometry (FO-LADS). The effects of various parameters on the extraction recovery were investigated. Under the optimized conditions and preconcentration of 10 mL of sample, the enrichment factor of 159 and the detection limit of 0.05 μgL(-1) were obtained. Validation of the method was performed by spiking-recovery method and comparison of results with those obtained by ET-AAS method.
authors.affiliation: Department of Analytical Chemistry, Faculty of Chemistry, University College of Science, University of Tehran, P.O. Box 14155-6455, Tehran, Iran.
authors.forename: Seyedeh Mahboobeh
authors.initials: SM
authors.lastname: Yousefi
authors.affiliation: Department of Analytical Chemistry, Faculty of Chemistry, University College of Science, University of Tehran, P.O. Box 14155-6455, Tehran, Iran. Electronic address: shemiran@khayam.ut.ac.ir.
authors.forename: Farzaneh
authors.initials: F
authors.lastname: Shemirani
mesh_terms: D002614:Chelating Agents / Q000737:chemistry; D002857:Chromium / Q000032:analysis*; D004160:Diphenylcarbazide / Q000737:chemistry; D060766:Drinking Water / Q000032:analysis; D005336:Fiber Optic Technology; D059627:Liquid Phase Microextraction; D012967:Sodium Dodecyl Sulfate / Q000737:chemistry; D013053:Spectrophotometry / Q000379:methods; D013501:Surface-Active Agents / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D002614:Chelating Agents; D060766:Drinking Water; D013501:Surface-Active Agents; D014874:Water Pollutants, Chemical; D002857:Chromium; C074702:chromium hexavalent ion; D004160:Diphenylcarbazide; D012967:Sodium Dodecyl Sulfate