A new complexing adsorbent was prepared by chemical modification of mesoporous silica Kieselgel 60 (d_p = 37–63 μm, average pore size 6 nm, specific surface area 425 m² g⁻¹) with 3-glycidoxypropyltrimethoxysilane and 2-[(phosphonomethyl)amino]acetic acid (PMA), commonly known as glyphosate. The prepared adsorbent was fully characterised using elemental analysis, thermal gravimetric analysis (TGA), acid–base potentiometric titration, Fourier Transform Infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), nitrogen adsorption isotherms at 77 K (BET), scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS). The concentration of bonded PMA groups calculated from the nitrogen content was 0.38 mmol per gram. The adsorption of transition metal ions on PMA functionalised silica (HEPMAS) was studied from aqueous solutions having different pH and the following selectivity was established, Zn(II) < Co(II) < Cd(II) < Mn(II) < Ni(II) < Cu(II). The calculated values of distribution coefficients D for the adsorption of ecotoxic metal ions on HEPMAS are 5.0 × 10⁴, 4.9 × 10⁵ and 2.6 × 10⁴ for Zn(II), Pb(II) and Cd(II), respectively.

Item Type:	Refereed Article
Keywords:	chemically modified silica, glyphosate, 2-[(phosphonomethyl)amino]acetic acid, functionalisation, metal removal, chelation
Research Division:	Chemical Sciences
Research Group:	Analytical chemistry
Research Field:	Separation science
Objective Division:	Expanding Knowledge
Objective Group:	Expanding knowledge
Objective Field:	Expanding knowledge in the chemical sciences
UTAS Author:	Caldarola, D (Mr Dario Caldarola)
UTAS Author:	Mitev, DP (Dr Dimitar Mitev)
UTAS Author:	Paull, B (Professor Brett Paull)
UTAS Author:	Nesterenko, PN (Professor Pavel Nesterenko)
ID Code:	93670
Year Published:	2014
Web of Science® Times Cited:	17
Deposited By:	Austn Centre for Research in Separation Science
Deposited On:	2014-08-12
Last Modified:	2017-10-27
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