Synthesis and characterisation of new hybrid sorbent, 2,2’- dipyridyl ketone functionalised SBA 15 and its application in solid-phase extraction of Pb(II) & Cd(II) from environmental samples

Abstract

ABSTRACT The mesoporous silica (SBA-15) was successfully functionalised with 2,2ʹ- dipyridyl ketone by post grafting method. The mesoporous structure and functionalization with organic moiety were examined using different physicochemical techniques such as Low angle X-ray diffraction (XRD), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), 13C NMR Spectroscopy, 29Si NMR Spectroscopy, N2 adsorption/desorption studies and TGA studies. The application of the hybrid material as sorbent in solid-phase extraction of Pb(II) and Cd(II) from environmental samples prior to determination by Flame Atomic Absorption Spectroscopy was studied. The analytical parameters such as pH, eluent type and its volume, sorbent dosage, flow rates, sample volume and effect of co-existing ions were studied and optimised. The prepared sorbent showed the preconcentration factor of 160 for both the metal ions with Limits of Detection of 0.20 µgL−1 and 0.27 µg L−1 and Limits of Quantification of 0.67 µg L−1 and 0.90 µg L−1 for Pb(II) and Cd(II) respectively. The adsorption capacity of the prepared sorbent found as 185.49 mg g−1 and 103.41 mg g−1 for Pb(II) and Cd(II), respectively. The proposed method was validated using a certified reference material NIST SRM-1640a with good agreement values. The proposed solid-phase extraction method was successfully applied to environmental water samples.