Determination of Cd2+, Cu2+, Mn2+, Pb2+, and Zn2+ in Aqueous Solution after Their Separation and Preconcentation as Metal - Dithizone Complexes on Activated Carbon

Maghazy, Marwa A.; Moalla, S. M. N.; Rashed, Mohamed Nageeb; Abd El Aziz, A.

doi:10.21608/aujes.2020.127578

Determination of Cd2+, Cu2+, Mn2+, Pb2+, and Zn2+ in Aqueous Solution after Their Separation and Preconcentation as Metal - Dithizone Complexes on Activated Carbon

Document Type : Original Research

Authors

¹ Chemistry Department, Faculty of Science, Aswan University

² Chemistry Department, Faculty of Science, Port Said University, Port Said, Egypt

³ Aswan University Faculty of Science

10.21608/aujes.2020.127578

Abstract

A simple and sensitive method for preconcentration and determination of Cd²⁺, Cu²⁺, Mn²⁺, Pb²⁺ and Zn²⁺ by flame atomic absorption spectrophotometer was developed. The method is based on the sorption of the studied elements as metal-dithizone complexes (M-DZ) on activated carbon (AC). The effect of various parameters (pH, shaking time, AC amount, ligand concentrations, eluent concentration, and solution volume) on quantitative sorption of metal-dithizone chelates using AC was investigated. The studied elements were eluted from AC simply with HNO₃acid. The results revealed that the optimum pH values for the sorption were 4 for Cu²⁺, 6 for Zn²⁺, 8 for Pb²⁺ and 10 for Cd²⁺ and Mn²⁺; shaking time was 10 min for Mn²⁺ and Pb²⁺, 30 min for Cu²⁺ and Zn²⁺ and 50 min for Cd²⁺; AC amount was 0.2 g for Zn²⁺, 0.3 g for Cd²⁺, 0.5 g for Pb²⁺, 0.6 g for Mn²⁺ and 0.8 g for Cu²⁺; metal: ligand ratio was found to be (1:2 ratio), and eluent concentration used was 1 mol L^-1 for Cd²⁺ and Mn²⁺, 2 mol L^-1 for Zn²⁺and 4 mol L^-1 for Cu²⁺ and Pb²⁺. The method can be applied with a preconcentration factor of 20 for Cd²⁺, and 40 for Cu²⁺, Mn²⁺, Pb²⁺, and Zn^2+.Preconcentration from various water samples showed recovery in the range 95-108 %, confirming the effectiveness and precision of the solid-phase method developed using activated carbon for enrichment of metals examined.

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