Flame atomic absorption determination of some metal ions in water samples after preconcentration on montmorillonite modified with trioctylamine

A column method using montmorrilonate with added trioctylamine as adsorbent was developed for the preconcentration and F-AAS determination of Fe, Cd, Zn, Ni, Mn, Cr and Cu ions in wastewater, tap water and river water samples. The influence of aqueous solution pH, amount of montmorillonite, flow rate of elution, different types and least amounts of elutes, and the effects of matrix ions on pre-concentration were investigated. The recoveries were >95%, and preconcentration factor was 250. The detection limits for Fe, Cd, Zn, Ni, Mn, Cr and Cu were found to be 0.09, 0.19, 0.08, 0.13, 0.21, 0.16 and 0.13 mu g/l, respectively. The relative standard deviation of the determination was