Facultade de Fisioterapia

Determination of metal impurities in electrolytic iron by GF-AAS using electric dispersion in liquid medium

Authors: Carlos Bendicho

Journal: Fresenius' Journal of Analytical Chemistry, 348: 353-355, 05/1994

DOI: https://doi.org/10.1007/BF00323134


A laboratory-built electrospark system, operated in liquid medium, is used as dispersion method for metallic samples. The metallic colloidal solutions formed upon electrocorrosion behave as typical lyophobic colloidal systems, which are highly stable. The parameters influencing the formation of the colloidal solutions are optimized so that the electrospark system can be used in combination with graphite furnace-atomic absorption spectrometry for trace metal determinations. Dispersion rates for electrolytic iron range from 50 to 125 μg min−1, depending on the power. The colloidal solutions show the same atomization behaviour as true solutions, which makes calibration with aqueous standards feasible. The method has been used to determine manganese, chromium und copper in the NIST SRM 665 electrolytic iron.