Determination of trace metal ions by AAS in natural water samples after preconcentration of pyrocatechol violet complexes on an activated carbon column

A simple preconcentration method is described for the determination of Cu, Mn, Co, Cd, Pb, Ni and Cr in water samples by flame AAS. Trace metal ions i n water were sorbed as pyrocatechol violet complexes on activated carbon co lumn at the pH range of 4-8, then eluted with 1 M HNO3 in acetone. The effe ct of major cations and anions of the natural water samples on the sorption of metal ions has been also investigated. The concentration of the metal i ons detected after preconcentration was in agreement with the added amount. The present method was found to be applicable to the preconcentration of C u, Mn, Co, Cd, Pb, Ni and Cr in natural water samples with good results suc h as R.S.D. from 3 to 8% (N = 10) and detection limits under 70 ng. 1(-1). (C) 2000 Elsevier Science B.V. All rights reserved.