A novel sorbent (MCM-41 immobilized with N-methylglucamine) for removal/preconcentration of boron from waters. Synthesis, characterization and applications to water samples

Abstract

Determination of boron has become an important task in a variety of analytical applications because of the increasing use of boron compounds in various industrial fields. Its concentration is generally low in many samples and this necessitates either the use of very sensitive analytical techniques or the application of suitable preconcentration methods prior to instrumental determination.In the present study, a novel sorbent was prepared by the functionalization of an inorganic support material, MCM-41, with N-methylglucamine for the uptake of boron from aqueous solutions prior to its determination by ICP-OES. Characterization of the newly synthesized material was performed using elemental analysis, XRD, DRIFTS, and BET analysis. Sorption behavior of the novel sorbent for boron was also investigated and found to obey Freundlich and Dubinin-Radushkevich (D-R) isotherm models. The maximum amount of B (as H3BO3) that can be sorbed by the sorbent was calculated from the D-R isotherm and was found to be 0.8 mmol of B per gram of sorbent. The applicability of the new sorbent for the removal/preconcentration of boron from aqueous samples was examined by batch method. It was found that the sorbent can take up 85 % of boron in 5 minutes whereas quantitative sorption is obtained in 30 minutes. Any pH greater than 6 can be used for sorption. The desorption from the sorbent was carried out with 1.0 M HNO3. For method validation, spike recovery tests were performed at various concentration levels in different water types and were found to be between 85-95 and 75-90 percent for ultra pure water and geothermal water, respectively.