Determination of butyltin compounds in environmental samples by isotope-dilution GC-ICP-MS.
Isotope-dilution analysis in combination with GC-ICP-MS detection has been applied to the determination of butyltin species in environmental samples. Different spikes containing the isotopically labeled butyltin species have been synthesized in the laboratory after optimization of the reaction conditions. The isotopic compositions of the tin species in the different spike solutions were determined by GC-ICP-MS after derivatization by aqueous ethylation with sodium tetraethylborate. Reverse isotope-dilution analysis was used for quantitation of the spike solutions by means of natural MBT, DBT, and TBT standards. The mixed spikes were used for simultaneous analysis of MBT, DBT and TBT in the certified reference materials, PACS-2, CRM 462, and CRM 646, with satisfactory results. The excellent agreement of the different speciation results obtained by use of the different spikes is a good indicator of the precision, accuracy, and reliability which can be achieved by using isotope-dilution analysis for trace metal speciation. Application of a double spike containing (119)Sn-enriched MBT (79.7 At%), (118)Sn-enriched DBT (86.7 At%), and (119)Sn-enriched TBT (83.1 At%) also enabled evaluation of the conditions resulting in quantitative extraction of the species from the solid matrix, in combination with possible alterations depending on the different extraction procedures used (mechanical shaking, ultrasounds, and microwaves). Mathematical equations used for this purpose computed the correct species concentrations directly and, additionally, the decomposition factors (from TBT to DBT and from DBT to MBT) after precise measurement of the (119)Sn/(120)Sn and (118)Sn/(120)Sn ratios for all butyltin species by GC-ICP-MS.
Alonso
J Ignacio García
JI
Department of Physical and Analytical Chemistry Faculty of Chemistry, Julián Clavería, 8, 33006 Oviedo, Spain. jiga@sauron.quimica.uniovi.es
Encinar
Jorge Ruiz
JR
González
Pablo Rodríguez
PR
Sanz-Medel
Alfredo
A
D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004787:Environmental Pollution / Q000032:analysis*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D009947:Organotin Compounds / Q000032:analysis*; D014220:Trialkyltin Compounds / Q000032:analysis
D009947:Organotin Compounds; D014220:Trialkyltin Compounds; C056189:di-n-butyltin; C011559:tributyltin