title: Determination of thiomersal by flow injection coupled with microwave-assisted photochemical online oxidative decomposition of organic mercury and cold vapor atomic fluorescence spectroscopy.
abstract: We developed a flow injection (FI) method for the determination of thiomersal (sodium ethylmercurithiosalicylate, C9H9HgNaO2S) based on the UV/microwave (MW) photochemical, online oxidation of organic mercury, followed by cold vapor generation atomic fluorescence spectrometry (CVG-AFS) detection. Thiomersal was quantitatively converted in the MW/UV process to Hg(II), with a yield of 97±3%. This reaction was followed by the reduction of Hg(II) to Hg(0) performed in a knotted reaction coil with NaBH4 solution, and AFS detection in an Ar/H2 miniaturized flame. The method was linear in the 0.01-2 μg mL(-1) range, with a LOD of 0.003 μg mL(-1). This method has been applied to the determination of thiomersal in ophthalmic solutions, with recoveries ranging between 97% and 101%. We found a mercury concentration in commercial ophthalmic solutions ranging between 7.5 and 59.0 μg mL(-1).
authors.affiliation: National Research Council of Italy, C.N.R., Istituto di Chimica dei Composti Organo Metallici-ICCOM-UOS Pisa, Area di Ricerca, Via G. Moruzzi 1, 56124 Pisa, Italy.
authors.forename: Beatrice
authors.initials: B
authors.lastname: Campanella
authors.forename: Massimo
authors.initials: M
authors.lastname: Onor
authors.forename: Marco Carlo
authors.initials: MC
authors.lastname: Mascherpa
authors.forename: Alessandro
authors.initials: A
authors.lastname: D'Ulivo
authors.forename: Carlo
authors.initials: C
authors.lastname: Ferrari
authors.forename: Emilia
authors.initials: E
authors.lastname: Bramanti
mesh_terms: D002851:Chromatography, High Pressure Liquid; D017022:Flow Injection Analysis; D008628:Mercury / Q000032:analysis*; D008872:Microwaves; D010084:Oxidation-Reduction; D013050:Spectrometry, Fluorescence / Q000379:methods*; D013849:Thimerosal / Q000032:analysis*
chemical_list: D013849:Thimerosal; D008628:Mercury
keywords: Atomic fluorescence spectrometry; Flow injection analysis; Mercury oxidation; Organic mercury-compounds; Thiomersal