Nano-clay as a solid phase microextractor of copper, cadmium and lead for ultra-trace quantification by ICP-MS

Abstract

Heavy metal microextraction and determination in daily used water is accurately achieved by applying nano-clay as an extractor. The conditions for adsorption/elution of Cu(II), Cd(II) and Pb(II) were investigated by adjusting the pH of samples, sample volume and the type of eluent. The nano-clay showed superior efficiency for microextraction of Cu(II), Cd(II) and Pb(II) at pH 2 using 2 mL of nitric acid (1 M) as the eluent. The microextraction procedure showed high recovery% by changing the sample volume from 15 mL to 70 mL. The preconcentration factor was found to be 37.5. The LOD and LOQ were 1.8, 1.3, and 1.9 μg L⁻¹ and 5.3, 3.9, and 5.7 μg L⁻¹ for Cu(II), Cd(II) and Pb(II) respectively. The addition/recovery from different water samples showed recovery% in the range 88–105 which confirms the efficiency and the accuracy of the developed solid phase microextraction using nano-clay for enrichment of Cu(II), Cd(II) and Pb(II).