Determination of Manganese, Copper, Cadmium and Lead by FAAS after Solid-Phase Extraction of Their Phenylpiperazine Dithiocarbamate Complexes on Activated Carbon

Solid phase extraction (SPE) techniques have been widely used for the pre-concentration and separation of trace metal ions in aqueous systems prior to their determination. Among the techniques available, the dithiocarbamate solid-phase extraction method is very selective because dithiocarbamate reagents do not react with many metals (alkali, earth alkali and some other metals such as Al and Cr) that are fairly abundant in environmental samples, and enrichment factors are generally high. Recently, this method has been applied prior to trace metal determination by UV-VIS1−2, ICP-AES3−5, AAS6−13 and electro-analytical methods14−16. The mechanism for the sorption of low levels of metal ions on solid adsorbent is still under investigation, but it is known that it is particularly related to the chelating agent and adsorbent; it is also known that metal retention can be improved while in the presence of a chelating or precipitating agent. In our previous work, some dithiocarbamate reagents were tested for the absorption of cadmium on microcrystalline naphthalene. It was found that the adsorption productivity of the metal ions on an adsorbent was directly connected with the dithiocarbamate reagent. In this study, potassium phenylpiperazine dithiocarbamate (KPPzDC) as a new chelating agent (Figure 1) was tested for the solid-phase extraction