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(Reference retrieved automatically from SciELO through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

W+Rh as permanent chemical modifier in simultaneous atomic absorption spectrometry: interference studies on As, Cd, Pb and Se determination

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Correia, P. R. M. ; Oliveira, P. V. ; Oliveira, E. ; Nomura, C. N. [4]
Total Authors: 4
Document type: Journal article
Source: Journal of the Brazilian Chemical Society; v. 15, n. 1, p. 75-82, Jan.-Feb. 2004.
Field of knowledge: Physical Sciences and Mathematics - Chemistry

A systematic study of Na+, K+, Ca2+, Mg2+, Cl-, NO3-, SO42- and PO43- interference on the simultaneous atomization of As, Cd, Pb and Se was carried out using an electrothermal atomic absorption spectrometer. The mixture 250 mg W + 250 mg Rh was thermally deposited on the graphite tube platform and used as permanent chemical modifier. The compromised heating program adjustments (Tp = 650 oC and Ta = 2200 oC) diminished the thermal decomposition and volatilization efficiency of the interfering species during the pyrolysis step. The Cl- and SO42- anions caused the most severe interference, while NO3- only affected the analytes' atomization when high amounts (> 27 mg) were used. The anion PO43- produced a strong negative interference on the Se absorbance signals. The presence of Na+, K+, Ca2+ and Mg2+ prejudiced mainly Cd, and the interference effects of Cl- salts were more pronounced than NO3- salts. (AU)