Superparamagnetic bi-functional composite bead for the thermal ionization mass spectrometry of plutonium(iv) ions. Issue 4 (4th January 2016)

• Record Type: Journal Article
• Authors: Paul, Sumana; Pandey, Ashok K.; Shah, Raju V.; Alamelu, D.; Aggarwal, Suresh K.
• Is Part Of: RSC advances. Volume 6:Issue 4(2016)
• Page Start: 3326
• Page End: 3334
• Publication Date: 2016-01-04
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c5ra18419c
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : Single resin bead-based thermal ionization mass spectrometry (TIMS) offers numerous advantages for Pu(iv ) determinations in complex aqueous samples. Abstract : Single resin bead-based thermal ionization mass spectrometry (TIMS) offers numerous advantages for Pu(iv ) determinations in complex aqueous samples. These include removal of the matrix and interfering ions by a one-step process, selective preconcentration of Pu(iv ) ions with a high chemical recovery, transportation without heavy shielding, avoiding the possibility of cross-contamination, and acting as a point source. The single-bead TIMS method reported in literature is based on an anion-exchange resin that lacks sorption-selectivity toward Pu(iv ) ions, and where the beads are not easily retrievable from a large volume sample. Therefore, silica-coated superparamagnetic Fe3 O4 embedded functionalized porous poly(ethersulfone) (PES) beads were developed for Pu(iv ) preconcentration and analysis by TIMS. The beads were functionalized with a phosphate bearing monomer along with or without a quaternary ammonium bearing monomer by UV-induced surface grafting. Since the beads were used in a highly acidic solution, the Fe3 O4 nanoparticles were protected with a silica coating formed by the hydrolysis and condensation of tetraethoxysilane. The PES porous beads were prepared by a phase inversion method. The monomers used for UV-grafting were 2-hydroxyethyl methacrylate ester and (3-acrylamidopropyl) trimethylammonium chloride. The functionalized beads were characterized by scanning electron microscopy, energy dispersive analysis, and vibrating sample magnetometry. The sorption studies indicated that the bi-functionalized PES beads consisting of phosphate and quaternary ammonium groups not only have a higher distribution coefficient ( K d ) for Pu(iv ) but also high selectivity toward Pu(iv ) ions in the presence of a large excess of U(vi ) ions ( K d (Pu(vi ))/ K d (U(iv )) = 11.5). The phosphate-functionalized PES beads showed comparable selectivity ( K d (Pu(vi ))/ K d (U(iv )) = 9.1), but a lower K d value for Pu(iv ). The quaternary ammonium-functionalized PES beads were found to have lower selectivity and K d values toward Pu(iv ) ions. The analytical performance of single bi-functionalized bead-based TIMS for the determination of Pu(iv ) using isotope dilution was compared with the solution-based TIMS, validated using the Pu isotopic standard reference material NIST SRM-947 and applied to real samples such as dissolver solutions and soil leach liquors.