Fast copper speciation screenings with solid-phase extraction cartridges using high-specific activity Cu-64

Solid-phase extraction (SPE) cartridges with different functional groups (c helating, ion-exchange, hydrophobic) may be useful for copper speciation de terminations of aqueous samples. Provided that each cartridge selectively e xtracts one species or a group of species, a fast screening of copper speci ation can be achieved by performing a series of extractions with different SPE cartridges and combining the results. For this purpose, the performance of five SPE cartridges was studied with respect to extraction selectivity using samples with known composition. Samples were spiked with a high-speci fic Cu-64 radiotracer to achieve easy detection of extracted copper species . Its high radioactivity per unit of mass ensures preservation of initial c hemical equilibria and composition of the sample. Results show that seconda ry interactions may take place on the extracting phase when relatively clea n samples are analyzed. Two natural water samples, viz. a ditch water and a seawater sample, were exposed to a series of extractions as well. Species distributions found for these samples generally correspond to expected dist ributions. Secondary interactions may be suppressed in these cases, as othe r metal species compete for these interactions.