Preconcentration of Zn2+ and Cu2+ ions from food and vegetable samples using modified activated carbon.
Ghaedi M., Tavallali H., Montazerozohori M., Zahedi E., Amirineko M., Khodadoust S., Karimipour G.
Author Affiliation: Department of Chemistry, Yasouj University, Yasouj, 75914-35, Iran.
Environmental Monitoring and Assessment 184 : 6583-6591
Abstract : In this work, two N/S-containing chelating agents 2-(4-methoxybenzylideneamino)thiophenol (2-4-MBAT) and 2-(4-chlorobenzylideneamino) benzenethiol (2-4-CBABT) were synthesized as new sorbents and were used for preconcentration of Zn2+ and Cu2+ ions in food and vegetable samples. In the proposed procedure, the trace amount of Zn2+ and Cu2+ ions from 250 mL of sample solution at pH=5.0 was preconcentrated by 1 g of activated carbon (AC) loaded with 15 mg of 2-4-MBAT and 2-4-CBABT separately. The breakthrough volumes (maximum sample volume that their metal ions quantitatively can be enriched) for solid-phase extraction (SPE) procedure based on the AC modified with 2-4-MBAT and 2-4-CBABT were 800 and 750 mL, respectively. The sorbed Zn2+ and Cu2+ ions were efficiently eluted by 8 mL of 4 mol L-1 HNO3 and preconcentration factor of 112.5 and 93.7 and experimental enhancement factor of 30 and 35 ions were obtained for Zn2+ and Cu2+, respectively. The application of this enrichment procedure allowed the extraction of trace metal ions with recoveries exceeding of 90%.