Determination of copper by FAAS after preconcentration with lead-4-methylpiperidinedithiocarbamate on microcrystalline naphthalene by solid-phase extraction

Abstract

By using the Pb-4-methylpiperidinedithiocarbamate complex (Pb(4-MPDC)(2)) on microcrystalline naphthalene in a column a method was developed for the preconcentration of copper in water samples prior to its determination by FAAS. In this method, copper in liquid phase quantitatively replaces lead on the Pb(4-MPDC)(2)-naphthalene solid phase in the column, forming solid Cu(4-MPDC)(2) complex. Afterwards, copper on Cu(4-MPDC)(2)-naphthalene can be easily eluted by potassium cyanide into the aqueous phase, and the Cu is measured by FAAS. The optimum experimental parameters such as pH, flow rate,sample volume, Pb(4-MPDC)2-naphthalene ratio, concentration of the potassium cyanide solution and effect of matrix ions for the preconcentration of copper were investigated. The obtained recovery was nearly 100 %, when the enrichment factor was 100 for standard solutions and spiked water samples. The proposed method has been employed for the determination of copper in various standard metal alloys and natural water samples.