title: Study of the degradation of butyltin compounds in surface water samples under different storage conditions using multiple isotope tracers and GC-MS/MS.
abstract: The degradation of butyltin compounds in surface water samples under different storage conditions has been studied. A triple spike solution, containing monobutyltin (MBT), dibutyltin (DBT) and tributyltin (TBT) labelled with a different tin isotope, was added to the sample to calculate the extent of the interconversion reactions among butyltin compounds. Real surface water samples (river water) were collected and stored in glass, polypropylene or polytetrafluoroethylene (PTFE) containers. The presence of light, addition of acetic acid, storage temperature (22, 4 or -18 °C), and the influence of a filtration step were evaluated. Moreover, Milli-Q water with and without the addition of a high concentration of humic acids was prepared in parallel and the results compared to those obtained from the real samples. The water samples were analysed by gas chromatography-tandem mass spectrometry (GC-MS/MS) in selected reaction monitoring (SRM) mode at two different storage times (2 weeks and 4 months after its preparation) to carry out both a short- and a long-term stability study. The lowest butyltin degradation was obtained when the samples were stored at -18 °C in the dark. Under these conditions, both TBT and DBT showed negligible dealkylation factors after 2 weeks. After 4 months, DBT dealkylation to MBT increased up to 19 % but TBT degradation was not observed.
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. rodriguezpablo@uniovi.es.
authors.forename: Pablo
authors.initials: P
authors.lastname: Rodríguez-González
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: D004784:Environmental Monitoring / Q000379:methods*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D007554:Isotopes / Q000032:analysis; D009947:Organotin Compounds / Q000032:analysis*; D045483:Rivers / Q000737:chemistry*; D053719:Tandem Mass Spectrometry; D013997:Time Factors; D014001:Tin / Q000737:chemistry; D014220:Trialkyltin Compounds / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D007554:Isotopes; D009947:Organotin Compounds; D014220:Trialkyltin Compounds; D014874:Water Pollutants, Chemical; C516409:mono-n-butyltin; C056189:di-n-butyltin; C011559:tributyltin; D014001:Tin
keywords: Multiple isotopic tracers; Storage conditions; Tributyltin; Whole water samples