N, O-rich graphene oxide based eggshell membrane polymer: preparation, characterization and its utility as nano sorbent for solid phase extraction of Pb (II) in various water samples.

Novel chemical modification of a natural polymer (soluble eggshell membrane protein (SEP)) with one of carbon nanostructures (graphene oxide (GO)) was used to prepare nano adsorption material. The graphene oxide-soluble eggshell membrane protein (GO-SEP) was characterized using FTIR, XRD, TG, DTG, DSC, SEM, STEM and particle size distribution thereafter was used for packing the solid phase extraction column. The SPE using GO-SEP as packing material was developed and enhanced by unique method depends on using dithiocarbamate as a chelating agent for the lead to determine its concentration in four different water samples by inductively coupled plasma - optical emission spectrometry (ICP-OES). The prepared chelating agent bis sodium barbituric acid dithiocarbamate (BADTC) was produced by treating barbituric acid with CS₂ in the presence NaOH. The factors that influence the preconcentration and determination of lead (pH, sample and eluent flow rates, concentration and type of eluents, a volume of sample, chelating agent concentration and interfering ions) have been examined in detail. Detection limits (LOD) (0.1 µg.L^−1) and the relative standard deviation (RSD%) were found lower than <0.12% (n=10, c=0.5 µg.L^−1). This new method has been successfully applied to determine lead in four water samples. [ABSTRACT FROM AUTHOR]