Summary: | The technology of supercritical fluid extraction (SFE) offers the opportunity to efficiently extract both relatively non-polar analytes as well as ionic materials (such as metal ions) that can be mobilized with the addition of complexing reagents. The nebulizer of a conventional flame atomic absorption spectrometer (FAAS) was modified to extend the range of metals amenable to on-line detection. The flow injection thermospray-FAAS (FI-TE-FAAS) interface provided efficient detection for a variety of less volatile elements (Co, Cr(III), Cr(VI), Fe, Ni, Mn and Al) present as ions in aqueous media or as complexes in the supercritical fluid (SC-CO2) carrier phase. The range of possible metal analytes that can be monitored has been increased over the nine elements (Ag, As, Cd, Cu, Hg, Mn, Pb, Se and Zn) that could be detected with an all-silica interface. The acetylacetonate complexes offered considerable potential for metal detection in an SC-CO2 carrier phase. Limits of detection (LODs) were used to compare the instrument responses to different metals. (Abstract shortened by UMI.)
|