| Abstract: | A sequential extraction technique was used to determine the chemical species of six metals (Fe, Mn, Cu, Zn, Pb, Cd) in suspended matter of the Kaoping and Tsengwen river basins. The samples were taken to cover the fresh and marine characteristics. The precision of the species determination was estimated by the relative difference between the concentration of total metal and the sum concentation of the five species. The accuracy for the measurement of total metal was examined from the recovery of metal spiking. The accuracy of the total determination is better than 94% and the precision of speciation is greater than 90%. Most of the studied metals were found in the Fe-Mn oxides and residual fractions except that Cd, Zn and Cu have significant amounts in the exchangeable, carbonate, and organic matter phases, respectively. Species other than residual fraction are generally considered as potentially available for biota in aquatic systems, and in most cases, metal pollution could be reflected from the variation of fraction distributions. |
