title: Combined cloud point-solid phase extraction by dispersion of TiO₂ nanoparticles in micellar media followed by semi-microvolume UV-vis spectrophotometric detection of zinc.
abstract: A new approach is presented in this paper by using dispersed TiO2 nanoparticles (TiO2-NPs) in a combined cloud point and solid phase extraction for the efficient preconcentration and determination of Zn(2+) in various samples. In this method Zn(2+) ions are adsorbed on TiO2-NPs and transferred into surfactant rich phase. Subsequently the Zn(2+) ions are desorbed from TiO2-NPs by a dithizone solution via forming a color complex which could be detected colorimetrically. The influence of chemical variables such as pH of the sample solution, electrolyte, amount of TiO2-NPs, type and volume of the eluent on the extraction system was studied. The calibration graph was linear in the range of 0.5-90.0 µg L(-1) of Zn(2+) (r=0.9996). An enrichment factor of 80 was achieved and the limit of detection for Zn(2+) was 0.33 µg L(-1). The relative standard deviation (RSD) for eight replicate measurements of 10 µg L(-1) and 60 µg L(-1) of Zn(2+) was 1.8% and 1.5% respectively. The proposed method was successfully applied to the quantitative determination of Zn(2+) in tap water, powder milk and Zinc sulfate tablet with satisfactory results.
authors: Department of Chemistry, College of Science, Shahid Chamran University, Ahvaz, Iran. Electronic address: npourreza@scu.ac.ir.
authors: Nahid
authors: N
authors: Pourreza
authors: Department of Chemistry, College of Science, Shahid Chamran University, Ahvaz, Iran.
authors: Tina
authors: T
authors: Naghdi
mesh_terms: D000327:Adsorption; D000818:Animals; D002138:Calibration; D006863:Hydrogen-Ion Concentration; D053768:Metal Nanoparticles / Q000737:chemistry*; D008823:Micelles; D008892:Milk / Q000737:chemistry; D015203:Reproducibility of Results; D052616:Solid Phase Extraction / Q000379:methods*; D013053:Spectrophotometry / Q000379:methods*; D013607:Tablets / Q000737:chemistry; D014025:Titanium / Q000737:chemistry*; D014881:Water Supply / Q000032:analysis; D015032:Zinc / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification; D019287:Zinc Sulfate / Q000737:chemistry
chemical_list: D008823:Micelles; D013607:Tablets; C009495:titanium dioxide; D019287:Zinc Sulfate; D014025:Titanium; D015032:Zinc
keywords: Cloud point extraction; Micellar media; Solid phase extraction; TiO(2) Nanoparticles; Zinc