title: Determination of lead and cadmium in titanium dioxide by differential pulse anodic stripping voltammetry.
abstract: A procedure for the simultaneous determination of lead and cadmium in TiO(2) by differential pulse anodic stripping voltammetry (ASV) has been developed. The key feature of the method is the use of triethanolamine (TEA) to remove titanium interference: TiO(2) undergoes acidic digestion with HF/H(2)SO(4) at atmospheric pressure, TEA is added to the HCl solution of the residue and the solution is analysed using a standard ASV instrumentation, equipped with a hanging mercury drop electrode. The calibration curves for both lead and cadmium are linear up to 50 mugl(-1) of solution, and the detection limits are 1 mugl(-1), corresponding to 1 mugg(-1) of TiO(2). Method reliability was tested by comparing the results with those given by electrothermal atomic absorption spectroscopy. The method has been successfully applied for determination of both contaminants in powdered titanium dioxide (raw materials) and in titanium dioxide-containing cosmetics (sunscreen products).
authors.affiliation: Dipartimento di Chimica Inorganica, Metallorganica e Analitica, University of Milan, Via Venezian 21, 20133 Milan, Italy.
authors.forename: Monica
authors.initials: M
authors.lastname: Panigati
authors.forename: Maria
authors.initials: M
authors.lastname: Piccone
authors.forename: Giuseppe
authors.initials: G
authors.lastname: D'Alfonso
authors.forename: Marica
authors.initials: M
authors.lastname: Orioli
authors.forename: Marina
authors.initials: M
authors.lastname: Carini