Investigation of preconcentration conditions some trace elements using expanded perlite modified with graphene oxide

In this study, preconcentration conditions of some trace elements using expanded perlite (EP) and graphene oxide modified expanded perlite (GO@perlite) were investigated. Most of perlite contains greater than 70% silica, the EP is inexpensive and abundantly available in Turkish markets so this could make it available candidate as an economical sorbent for removing heavy metals such as lead, copper, cadmium and chromium. Firstly, preconcentration conditions of some trace elements using expanded perlite adsorption recovery is %100, but preconcentration process is not reproducible so expanded perlite is modified with graphene oxide. A new sorbent was synthesized by covalently binding GO sheets to the silika based perlite. The carboxy groups of GO were linked to the amino groups (3-aminopropytrimethoxysilane, APTS- % 96) of an aminoterminated silika sorbent (aminosilika). It was dried at 80 ºC and then the dried sorbent sieved by a 63 µm sieve. Column technique was used and for this purpose, 0,8 mm glass column was used. To determine optimum conditions, several parameters such as pH, eluent type and concentration, flow rate, breakthrough volume, adsorption capacity and foreign ions effect were studied. Adsorption capacity of GO@perlit was found to be 140,8 and 357,1 mg g-1 for Cu(II) and Pb(II) ions, respectively. The modification, size and morphology of sorbent was characterized by FT-IR, SEM, XRD and TGA/DTA. The proposed method was succesfully applied spiked analysis of copper and lead in real tap water and fruity sodas samples and flame atomic absorption spectrometry was used for analysis of trace elements.