Trace metals have been concentrated onto activated charcoal by using oxalic acid, iminodiacetic acid, and 8-hydroxyquinoline. The charcoal was directly analyzed in an ICP by placing several particles in a direct sample insertion (DSI) cup, or fabricating a DSI probe with an activated charcoal cap. Detection limits in the tens to hundreds of parts per trillion were found for Pb, Cd, Zn, and Cu. The recovery for Cu was 2–5% but may be improved by reactivation of the plasma-cleaned charcoal. Cleaning the charcoal, derived from wood, in the plasma prior to adsorption was necessary to remove trace metals.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.