Determination of Neodymium (III) in Human Plasma and Environmental Samples with Poly(allyl glycidyl ether/Iminodiacetic Acid-co-dimethylacrylamide) Brushes Grafted onto Siliceous Support

摘要

The increased utilization of mechanically stable synthetic matrices, particularly silica gel as a solid support and its surface modification by covalent polymer grafting through a spacer unit for extractive concentration oftrace neodymium in human biological fluid and environmental samples are highlighted in the present article. First, silica surface was modified by silylation with 3-mercaptopropyltrimethoxysilane followed by graft polymerization. Modified silica was grafted with polymer containing a functional monomer for metal chelating, poly[1-(N, N-bis-carboxymethyl)amino-3-allylglycerol-co-dimethylacrylamide] (poly(AGE/IDA-co-DMAA). The resulting sorbent has been characterized by FTIR, elemental analysis, FT-Raman, thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). The sorption capacity of the functionalized sorbent was 53.3 mg g~(-1). The chelating sorbent can be reused for 15 cycles of sorption-desorption without any significant change in sorption capacity. The profile of neodymium uptake on this sorbent reflects good accessibility of the chelating sites in the poly(AGE/IDA-co-DMAA)-grafted silica gel. Scatchard analysis revealed that the homogeneous binding sites were formed in the polymers. The equilibrium adsorption data of Nd(III) on modified sorbent were analyzed by Langmuir, Freundlich, Temkin, and Redlich-Peterson models. The method was successfully applied for determination of neodymium ions in human plasma and sea water sample.