Diaion SP-850 resin as a new solid phase extractor for preconcentration-separation of trace metal ions in environmental samples

A solid phase extraction method was developed for the preconcentration and separation of trace amounts of chromium, manganese, iron, cobalt, copper, cadmium and lead from environmental samples by complexation with alpha-benzoin oxime followed by adsorption onto Diaion SP-850-solid phase extraction column. One molar per liter HNO₃ was used as eluent. The recoveries of analytes at pH 8.0 with 700 mg of resin were greater than 95% without interference from alkaline, earth alkaline and some metal ions. The detection limits by three sigma for analyte ions were 0.65 μg l^-1 for Cr(III), 0.42 μg l^-1 for Mn(II), 0.28 μg l^-1 for Fe(III), 0.73 μg l^-1 for Co(II), 0.30 μg l^-1 for Cu(II), 0.47 μg l^-1 for Cd(II) and 0.50 μg l^-1 for Pb(II). The validation of the procedure was performed by the analysis of the certified standard reference materials. The presented procedure was applied to the determination of analytes in tap, river and sea waters, rice, wheat, canned tomato and coal samples with successfully results (recoveries greater than 95%, R.S.D.'s lower than 8%).