Capillary zone electrophoresis for U(VI) and short chain carboxylic acid sorption studies on silica and rutile

• Published in: Talanta (Oxford) Vol. 83; no. 5; pp. 1595 - 1600
• Main Authors: Sladkov, Vladimir, Zhao, Yujia, Mercier-Bion, Florence
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.02.2011; Elsevier
• Subjects: Absorption; Analytical chemistry; Applied sciences; Capillary zone electrophoresis; Carboxylic acids; Carboxylic Acids - analysis; Carboxylic Acids - chemistry; Chains; Chemical Physics; Chemistry; Chromatographic methods and physical methods associated with chromatography; Electrophoresis; Electrophoresis, Capillary; Exact sciences and technology; Global environmental pollution; Methyl alcohol; Other chromatographic methods; Physics; Pollution; Rutile; Separation; Silica; Silicon dioxide; Silicon Dioxide - chemistry; Sorption; Titanium - chemistry; Uranium; Uranium - chemistry; Sorption; Uranium; Carboxylic acids; Capillary zone electrophoresis; Rutile; Silica; Zone electrophoresis; Oxalate; Check; Product; Selectivity; Organic acids; Accuracy; Carboxylic acid; Formic acid; Standard curve; pH; Polarity; Carbonates; Methanol; Capillary electrophoresis; Use; Matrix effect; Acetate; Concentration; Method; Perchlorates; Dissolution; Silicon IV; Ultraviolet detector; Oxalic acid; Ionic strength; Simultaneous measurement; Uranium VI; Bromides; Formate; End; Uranyl
• ISSN: 0039-9140; 1873-3573
• DOI: 10.1016/j.talanta.2010.11.055

Capillary zone electrophoresis was used to study the uranyl and short chain carboxylic acid sorption on silica and rutile. The separation and the simultaneous determination (in a single run) of a number of short chain carboxylic acids (oxalic, formic, acetic and propionic) and U(VI) with direct UV detection is developed for the analysis of solutions after the sorption experiments. The reverse polarity mode is used (the injection is performed at the negative end). The matrix effect of Si(IV) (possible silica dissolution product) and perchlorate (added for constant ionic strength in sorption experiments) on the separation of U(VI) and organic acids is investigated. The influence of methanol addition in carrier electrolyte on the separation selectivity of given analytes is also studied. Under the chosen conditions (carbonate buffer (ionic strength of 0.1M), pH 9.8, 0.15mM of tetradecyltrimethylammonium bromide, 25% (v/v) of methanol) the calibration curves are plotted. They are linear in two ranges of concentration from ∼1×10−5 to ∼1×10−3M for oxalate, acetate, propionate, U(VI) and ∼1×10−4 to ∼1×10−3 for formate. The accuracy of the procedure is checked by the “added-found” method in simulation solutions. The relative standard deviations of the concentrations found are within the range of 1–10% and the recovery is in the range of 90–115%. This method is applied for the analysis of aqueous samples issued from sorption experiments on silica and rutile. The obtained results indicate that the given organic acids decrease uranium sorption both on silica and rutile. These experiments demonstrate that short chain carboxylic acids can influence the mobility and the chemistry of U(VI) in the environment.