title: Simultaneous determination of mono-, di- and tributyltin in environmental samples using isotope dilution gas chromatography mass spectrometry.
abstract: The development of a rapid, precise and accurate speciation method for the simultaneous determination of mono-, di- and tributyltin in environmental samples is described. The method is based on using isotope dilution gas chromatography/mass spectrometry (GC/MS) with electron ionization, a widely used technique in routine testing laboratories. A mixed spike containing (119)Sn-enriched monobutyltin (MBT), dibutyltin (DBT) and tributyltin (TBT) was used for the isotope dilution of the samples. Five molecular ions were monitored for each analyte, corresponding to the (116)Sn, (117)Sn, (118)Sn, (119)Sn and (120)Sn isotopes. The detection at masses corresponding to (116)Sn and (117)Sn were used to correct for m + 1 and m + 2 contributions of (13)C from the organic groups attached to the tin atom on the (118)Sn, (119)Sn and (120)Sn masses with simple mathematical equations and the concentrations of the butyltin compounds were calculated based on the corrected (118)Sn/(119)Sn and (120)Sn/(119)Sn isotope ratios. The (119)Sn-enriched multispecies spike was applied with satisfactory results to the simultaneous determination of MBT, DBT and TBT in three certified reference materials: two sediments, PACS-2 and BCR 646, and the mussel tissue CRM 477. The method was compared with a previously published GC/inductively coupled plasma MS isotope dilution procedure, developed in our laboratory, by injecting the same samples into both instruments. Comparable analytical results in terms of precision and accuracy are demonstrated for both atomic and molecular mass spectrometric detectors. Thus, reliable quantitative organotin speciation analysis can be achieved using the more widespread and inexpensive GC/MS instrument.
authors.affiliation: Faculty of Chemistry, Department of Physical and Analytical Chemistry, University of Oviedo, Julián Clavería 8, 33006 Oviedo, Spain.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Centineo
authors.forename: Pablo
authors.initials: P
authors.lastname: Rodríguez-González
authors.forename: Elisa
authors.initials: E
authors.lastname: Blanco González
authors.forename: J Ignacio
authors.initials: JI
authors.lastname: García Alonso
authors.forename: Alfredo
authors.initials: A
authors.lastname: Sanz-Medel
mesh_terms: D000818:Animals; D049872:Bivalvia / Q000737:chemistry; D004787:Environmental Pollution / Q000032:analysis*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D019015:Geologic Sediments / Q000737:chemistry*; D009947:Organotin Compounds / Q000032:analysis* / Q000737:chemistry; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014220:Trialkyltin Compounds / Q000032:analysis* / Q000737:chemistry
chemical_list: D009947:Organotin Compounds; D014220:Trialkyltin Compounds; C056189:di-n-butyltin; C011559:tributyltin