Determination of cadmium by FAAS after solid-phase extraction of its 1-benzylpiperazinedithiocarbamate complex on micro crystalline naphthalene

Abstract

By using 1-benzylpiperazinedithiocarbamate (1-BPzDC) as a new reagent, a method of solid-phase extraction is described for the pre-concentration of cadmium in water samples prior to its determination by flame atomic. absorption spectrometry (FAAS). This method is based on the fact that cadmium forming in aqueous phase cadmium 1-benzylpiperazinedithiocarbamate complex (Cd(1-BPzDC)(2)) can be extracted with micro crystalline naphthalene on solid phase, then back-extracted with potassium cyanide solution into aqueous phase and measured by FAAS. The optimum experimental parameters for the extraction and back-extraction of cadmium were investigated. The obtained recovery was nearly 97% when the enrichment factor was 500 for spiked cadmium solutions. The interfering effects of M(II), Fe(III), Cu(II), Ni(H), Pb(H), Cr(III), H-(II), Zn(II), Bi(III), Ag(I), acetate, tartarate, oxalate, citrate, EDTA, cyanide, fluoride, chloride, bromide and iodide were investigated, and almost were eliminated except for EDTA and cyanide. The detection limit (0.034 mugmL(-1)) and the determination limit of the proposed method (0.114 mugmL(-1)) were evaluated as the concentration corresponding to three times and ton times the standard deviation of the blank signal, respectively.