An efficient mercapto-functionalized organic-inorganic hybrid sorbent for selective separation and preconcentration of antimony(iii) in water samples

Abstract

This work reported on the application of mercapto-functionalized silica-supported organic-inorganic hybrid sorbent as a solid phase extraction (SPE) extractant for effective separation and preconcentration of Sb(iii) species in real water samples. The influences of pH, sorbent amounts, flow rates and the concentration of eluent on the adsorption and desorption of Sb(iii) species had been evaluated. The recovery of Sb(iii) species at pH 5 with 100 mg mercapto-functionalized hybrid sorbent at the flow rate of 5.0 mL min^-1 was greater than 95% without interference from all of metal ions tested. The trapped Sb(iii) species by extractant was then eluted with 5% HCl solution at the flow rate of 5.0 mL min^-1. The proposed procedure permitted large enrichment factors of about 200 and higher for 10 μg L^-1 of Sb(iii) species. The merits of analytical figures for the determination of Sb(iii) species were as follows: detection limit (3σ, n = 11), 2 ng L^-1; precision, 1.6% (n = 11) for 10 μg L^-1 of Sb(iii) species; the linear calibration curve presented in the concentration range of 1.0-200.0 μg L^-1. The validity of the proposed procedure was checked by the analysis of standard reference materials. Excellent agreement between the analytical results and the certified values (t-test at 95% confidence level) was found. The mercapto-functionalized hybrid sorbent as a SPE extractant was applied to the determination of Sb(iii) species in various water samples with satisfactory results.