Tellurium speciation analysis using hydride generation in situ trapping electrothermal atomic absorption spectrometry and ruthenium or palladium modified graphite tubes.
Talanta
; 102: 59-67, 2012 Dec 15.
Article
em En
| MEDLINE
| ID: mdl-23182575
ABSTRACT
Speciation of tellurium can be achieved by making use of different kinetic behaviors of Te(IV) and Te(VI) upon their reaction with sodium borohydride using hydride generation. While Te(IV) can form H(2)Te, Te(VI) will not form any volatile species during the course of hydride formation and measurement by atomic absorption spectrometry. Quantitative reduction of Te(VI) was achieved through application of a microwave assisted prereduction of Te(VI) in 6.0 mol/L HCl solution. Enhanced sensitivity was achieved by in situ trapping of the generated H(2)Te species in a previously heated graphite furnace whose surface was modified using Pd or Ru. Overall efficiency for in situ trapping in pyrolytically coated graphite tube surface was found to be 15% when volatile analyte species are trapped for 60s at 300°C. LOD and LOQ values were calculated as 0.086 ng/mL and 0.29 ng/mL, respectively. Efficiency was increased to 46% and 36% when Pd and Ru surface modifiers were used, respectively. With Ru modified graphite tube 173-fold enhancement was obtained over 180 s trapping period with respect to ETAAS; the tubes could be used for 250 cycles. LOD values were 0.0064 and 0.0022 ng/mL for Pd and Ru treated ETAAS systems, respectively, for 180 s collection of 9.6 mL sample solution.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Espectrofotometria Atômica
/
Telúrio
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Poluentes Químicos da Água
Idioma:
En
Ano de publicação:
2012
Tipo de documento:
Article