Determination of Mo and Bi in steels by electrothermal atomic absorption spectrometry after complexation and sorption on activated carbon.
A simple method for the preconcentration of Mo and Bi in steels is proposed. The analytes are complexed with the ammonium salt of dithiophosphoric acid O,O-diethyl ester and sorbed onto activated carbon. After desorption into a small volume of nitric acid at low pH, Mo and Bi are determined by electrothermal atomic absorption spectrometry. Iron(III) is reduced to Fe(II), which is not complexed and not significantly retained on the carbon. Enrichment factor of 23 and 26 were obtained for Mo and Bi, respectively. The method was applied to the analysis of four certified reference steels, after acid dissolution in a microwave system and good agreement was obtained with the certified or recommended values.
Giacomelli
M B
MB
Departamento de Quimica da Universidade Federal de Santa Catarina, 88040-900 Florianópolis, S.C., Brazil.
da Silva
J B
JB
Curtius
A J
AJ