title: Cloud point extraction of uranium using H₂DEH[MDP] in acidic conditions.
abstract: A procedure has been developed for the cloud point extraction (CPE) of uranium (VI) using H2DEH[MDP] (P,P-di(2-ethylhexyl) methanediphosphonic acid) with inductively coupled plasma coupled to mass spectrometry (ICP-MS). The method is based on the modification of the cloud point temperature using cetyl trimethyl ammonium bromide (CTAB) and KI. Optimal conditions of extraction were found using a cross-optimization of every parameter (non-ionic and ionic surfactant concentrations, chelating agent concentration, pH and the extraction, and phase separation temperatures). Furthermore, the figures of merit of the methodology were assessed (limit of detection, limit of quantification, recovery, sensibility, and linear range) and are reported. Quantitative extraction (99 ± 0.5%) was obtained in drinking water samples over a wide range of uranium concentrations. The approach was also validated using drinking (SCP EP-L-3 and SCP EP-H-3), and wastewater (SCP EU-L-3) certified materials. Interferences from most critical anions and cations were evaluated to determine the reliability of the method. The proposed method showed robustness since its performance is maintained over a wide range of pH and metal ion concentrations.
authors.affiliation: Laboratoire de radioécologie, Département de chimie, Université Laval, 1045 Avenue de la Médecine, Québec, QC, Canada G1V 0A6.
authors.forename: Charles
authors.initials: C
authors.lastname: Labrecque
authors.forename: Sabrina
authors.initials: S
authors.lastname: Potvin
authors.forename: Laurence
authors.initials: L
authors.lastname: Whitty-Léveillé
authors.forename: Dominic
authors.initials: D
authors.lastname: Larivière
mesh_terms: D000077286:Cetrimonium; D002593:Cetrimonium Compounds / Q000737:chemistry; D002614:Chelating Agents / Q000737:chemistry; D005591:Chemical Fractionation / Q000379:methods*; D011232:Chemical Precipitation; D004164:Diphosphonates / Q000737:chemistry*; D060766:Drinking Water / Q000032:analysis; D057230:Limit of Detection; D013058:Mass Spectrometry / Q000379:methods; D008823:Micelles; D017830:Octoxynol; D011092:Polyethylene Glycols / Q000737:chemistry*; D013501:Surface-Active Agents / Q000737:chemistry*; D014501:Uranium / Q000302:isolation & purification*; D062065:Wastewater / Q000032:analysis; D014875:Water Pollutants, Radioactive / Q000302:isolation & purification*
chemical_list: D000077286:Cetrimonium; D002593:Cetrimonium Compounds; D002614:Chelating Agents; D004164:Diphosphonates; D060766:Drinking Water; D008823:Micelles; D017830:Octoxynol; D011092:Polyethylene Glycols; D013501:Surface-Active Agents; D014501:Uranium; D062065:Wastewater; D014875:Water Pollutants, Radioactive; C027474:methylene diphosphonate; C010615:Nonidet P-40