Iranian Nanotechnology Society International Journal of Nanoscience and Nanotechnology 1735-7004 7 1 2011 03 01 Application of Modified Nanoclay Sorbent for Separation and Preconcentration Trace Amount of Cobalt 21 27 3950 EN D. Afzali Nanochemistry and Environment Department, Research Institute of Environmental Sciences, International Center for Science, High Technology & Environmental Sciences, Kerman, I.R. Iran Z. Biniaz Chemistry Department, Shahid Bahonar University of Kerman, Kerman, I.R. Iran A. Mostafavi Chemistry Department, Shahid Bahonar University of Kerman, Kerman, I.R. Iran Journal Article 2010 11 28 The present article reports on the application of modified organo nanoclay as a green, easily prepared and stable solid sorbent for the preconcentration of trace cobalt ion in aqueous solution. The organo nanoclay was modified by adsorption of 5-(4-dimethyl amino-benzylidene) rhodanin reagent onto it. The sorption of Co2+ ions was quantitative in the pH range of 7.0 to 8.5, whereas quantitative desorption occurs instantaneously in 5.0 mL of 2.0 mol L-1 HNO3. The eluted solution was aspirated directly into the flame of atomic absorption spectrometry (FAAS). Linear range for determination of cobalt was maintained between 0.176 ng mL-1 to 15.0 μg mL-1 in initial solution. Relative standard deviation for ten replicated determination of 1.0 μg mL-1 of cobalt was ±2.34% . Detection limit was 0.1 ng mL-1 in initial solution (3Sbl, n=10) and preconcentration factor was 170. The sorption capacity of modified nanoclay for Co (II) was evaluated 0.56 mg per g of sorbent. The effects of the experimental parameters, including the sample pH, flow rates of sample and eluent solution, eluent type,  breakthrough volume and interference ions were studied for preconcentration of Co2+. The proposed method was applied for determination of cobalt in water samples. https://www.ijnnonline.net/article_3950_bb702465f3c3141263ddd046c9585b27.pdf