title: Preparation, preservation and application of pure isotope-enriched phenyltin species.
abstract: A method combining liquid/liquid extraction and chromatographic fractionation has been developed for the preparation of pure monophenyltin (MPhT), diphenyltin (DPhT), and triphenyltin (TPhT), synthesized from isotope-enriched Sn metal using phenylation of SnI(4) in diethylether (DEE) followed by quenching with HBr and water. After two successive extractions of the aqueous HBr phase with DEE, >99% of both DPhT and TPhT was recovered in the combined DEE phase and 94% of the MPhT remained in the aqueous phase. The MPhT in the aqueous phase was extracted into dichloromethane. The organic phases were vaporized and the PhTs were redissolved in MeOH/water/acetic acid/sodium acetate (59/30/6/8, v/v/v/w), which was also used as storing solution. Aliquots of the two solutions containing either DPhT and TPhT or MPhT were injected into a silica-based C(18) column for isolating and purifying single species. The yields of pure MPhT, DPhT, and TPhT, each synthesized from isotope-enriched (118)Sn metal, (122)Sn metal, and (124)Sn metal, were better than 99%. After chromatographic separation, the single phenyltin compounds were mixed to prepare a spike for multiple-isotope species-specific isotope dilution (MI-SSID). MI-SSID was successfully used to determine phenyltin compounds in the certified reference material, mussel tissue BCR CRM-477. At -20 degrees C, all of the fractionated phenyltin species were stable in the storage solution for at least 197 days. When these standards were stored at 4 degrees C or 22 degrees C, 4-6% of the DPhT and TPhT degraded within 27 days. The degradation of DPhT and TPhT increased with the ionic strength and acidity of the storage solution.
authors.affiliation: Analytical Chemistry, Department of Chemistry, Umeå University, 901 87 Umeå, Sweden.
authors.forename: Dong
authors.initials: D
authors.lastname: Nguyen Van
authors.forename: Siva Rama Krishna
authors.initials: SR
authors.lastname: Muppala
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Frech
authors.forename: Solomon
authors.initials: S
authors.lastname: Tesfalidet
mesh_terms: D005591:Chemical Fractionation / Q000379:methods; D002849:Chromatography, Gas / Q000379:methods; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D007554:Isotopes; D009947:Organotin Compounds / Q000032:analysis / Q000138:chemical synthesis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013997:Time Factors
chemical_list: D007554:Isotopes; D009947:Organotin Compounds; C063612:diphenyltin; C063613:phenyltin; C030665:triphenyltin