Mass Balance of Metal Species in Supercritical Fluid Extraction Using Sodium Diethyldithiocarbamate and Dibutylammonium Dibutyldithiocarbamate

DOI PDF Web Site Web Site Web Site 43 References

Search this article

Abstract

The objective of this work is to track the amount of metal complexes distributed in the extraction cell, collection vial, and tubing used in supercritical fluid extraction (SFE) systems after progressive removal of metal ions in supercritical carbon dioxide (SC-CO2). Sodium diethyldithiocarbamate (NaDDC) and dibutylammonium dibutyldithiocarbamate (DBDC) ligands were used to form complexes with Cd, Cu, Pb, and Zn and CO2/5% methanol as a supercritical fluid. The mass balance of metal complexes were obtained before and after extraction, and metals in different locations in the system were flushed out using an organic solvent and nitric acid (HNO3). These results infer that the stability constant (β) of the metal-ligand complex has a strong correlation with SFE. Because of the composition of the stainless-steel cell, Fe, Cr, and Ni or other trace elements in the cell might interfere with the mass balance of metal complexes in SFE due to an exchange mechanism taking place between the cell and the sample.

Journal

  • Analytical Sciences

    Analytical Sciences 22 (3), 363-369, 2006

    The Japan Society for Analytical Chemistry

References(43)*help

See more

Report a problem

Back to top