Modification of TiO2 Nanoparticles with 1-Nitroso-2-naphtol and Its Application to the Preconcentration of Cobalt

Cobalt is an essential element for living species and its monitoring in environmental, biological and pharmaceutical samples is of great importance. It is usually present at trace levels in various samples. Therefore a preconcentration step is often required prior to its determination. One of the most widely used techniques for preconcentration is solid phase extraction (SPE). Various substances have been proposed and applied as extractants in SPE, such as modified silica, alumina, active carbon, and so on [1, 2].Nanomaterials, which are clusters of atoms or molecules of metal and oxide‚ ranging in size from 1 nm to almost 100 nm have interesting properties. One of these properties is that most of the atoms are on the surface of these materials. The surface atoms are unsaturated‚ and can therefore bind with other atoms [3]. Consequently‚ the nanometer-sized materials usually have high chemical activity and adsorption capacity and hence can be used as sorbents for SPE. However, the chemical or physical modification of the nanoparticle surface is usually needed to improve its selectivity and/or affinity towards ions [4].In the present work, 1-nitroso-2-naphthol (NN) has been immobilized on sodium dodecyl sulfate (SDS) coated TiO2 nanoparticles and used as a selective sorbent for preconcentration of cobalt ions