title: Determination of ultratrace levels of tributyltin in waters by isotope dilution and gas chromatography coupled to tandem mass spectrometry.
abstract: The current EU legislation lays down the Environmental Quality Standards (EQS) of 45 priority substances in surface water bodies. In particular, the concentration of tributyltin (TBT) must not exceed 0.2ngL(-1) and analytical methodologies with a Limit of Quantification (LOQ) equal or below 0.06ngL(-1) are urged to be developed. This work presents a procedure for the determination of ultratrace levels of TBT in water samples by Isotope Dilution and GC-MS/MS operating in Selected Reaction Monitoring (SRM) mode which meets current EU requirements. The method requires the monitorization of five consecutive transitions (287>175 to 291>179) for the sensitive and selective detection of TBT. The measured isotopic distribution of TBT fragment ions was in agreement with the theoretical values computed by a polynomial expansion algorithm. The combined use of Tandem Mass Spectrometry, a sample volume of 250mL, the preconcentration of 1mL of organic phase to 30μL and an injection volume of 25μL by Programmed Temperature Vaporization provided a LOQ of 0.0426ngL(-1) for TBT (calculated as ten times the standard deviation of nine independent blanks). The recovery for TBT calculated in Milli-Q water at the EQS level was 106.3±4%. A similar procedure was also developed for the quantification of dibutyltin (DBT) and monobutyltin (MBT) in water samples showing satisfactory results. The method was finally implemented in a routine testing laboratory to demonstrate its applicability to real samples obtaining quantitative recoveries for TBT at the EQS level in mineral water, river water and seawater.
authors.affiliation: Department of Physical and Analytical Chemistry, Faculty of Chemistry, University of Oviedo, Julián Clavería 8, 33006 Oviedo, Spain.
authors.forename: Andrés
authors.initials: A
authors.lastname: Rodríguez-Cea
authors.affiliation: Department of Physical and Analytical Chemistry, Faculty of Chemistry, University of Oviedo, Julián Clavería 8, 33006 Oviedo, Spain. Electronic address: rodriguezpablo@uniovi.es.
authors.forename: Pablo
authors.initials: P
authors.lastname: Rodríguez-González
authors.affiliation: IPROMA S.L. Investigación y Proyectos de Medio Ambiente, Camino de la Raya 46, 12005 Castellón, Spain.
authors.forename: Nuria
authors.initials: N
authors.lastname: Font Cardona
authors.affiliation: IPROMA S.L. Investigación y Proyectos de Medio Ambiente, Camino de la Raya 46, 12005 Castellón, Spain.
authors.forename: José Luís
authors.initials: JL
authors.lastname: Aranda Mares
authors.affiliation: IPROMA S.L. Investigación y Proyectos de Medio Ambiente, Camino de la Raya 46, 12005 Castellón, Spain.
authors.forename: Salomé
authors.initials: S
authors.lastname: Ballester Nebot
authors.affiliation: Department of Physical and Analytical Chemistry, Faculty of Chemistry, University of Oviedo, Julián Clavería 8, 33006 Oviedo, Spain.
authors.forename: J Ignacio
authors.initials: JI
authors.lastname: García Alonso
mesh_terms: D005618:Fresh Water / Q000737:chemistry; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D007201:Indicator Dilution Techniques; D007554:Isotopes; D008900:Mineral Waters / Q000032:analysis; D009947:Organotin Compounds / Q000032:analysis; D012623:Seawater / Q000737:chemistry; D053719:Tandem Mass Spectrometry / Q000379:methods; D014220:Trialkyltin Compounds / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D007554:Isotopes; D008900:Mineral Waters; D009947:Organotin Compounds; D014220:Trialkyltin Compounds; D014874:Water Pollutants, Chemical; C516409:mono-n-butyltin; C056189:di-n-butyltin; C011559:tributyltin
keywords: EU Water Framework Directive; GC–MS/MS; Isotope Dilution Mass Spectrometry; Tributyltin