title: Total synthesis of isotopically enriched Si-29 silica NPs as potential spikes for isotope dilution quantification of natural silica NPs.
abstract: A new method was developed for the preparation of highly monodisperse isotopically enriched Si-29 silica nanoparticles ((29)Si-silica NPs) with the purpose of using them as spikes for isotope dilution mass spectrometry (IDMS) quantification of silica NPs with natural isotopic distribution. Si-29 tetraethyl orthosilicate ((29)Si-TEOS), the silica precursor was prepared in two steps starting from elementary silicon-29 pellets. In the first step Si-29 silicon tetrachloride ((29)SiCl4) was prepared by heating elementary silicon-29 in chlorine gas stream. By using a multistep cooling system and the dilution of the volatile and moisture-sensitive (29)SiCl4 in carbon tetrachloride as inert medium we managed to reduce product loss caused by evaporation. (29)Si-TEOS was obtained by treating (29)SiCl4 with absolute ethanol. Structural characterisation of (29)Si-TEOS was performed by using (1)H and (13)C nuclear magnetic resonance (NMR) spectroscopy and Fourier-transform infrared (FTIR) spectroscopy. For the NP preparation, a basic amino acid catalysis route was used and the resulting NPs were analysed using transmission electron microscopy (TEM), small angle X-ray scattering (SAXS), dynamic light scattering (DLS) and zeta potential measurements. Finally, the feasibility of using enriched NPs for on-line field-flow fractionation coupled with multi-angle light scattering and inductively coupled plasma mass spectrometry (FFF/MALS/ICP-MS) has been demonstrated.
authors.affiliation: Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences (IMEC RCNS HAS), H-1117 Budapest, Magyar Tudósok körútja 2., Hungary; LGC Limited, Queens Road, Teddington, Middlesex TW11 0LY, UK.
authors.forename: Marcell
authors.initials: M
authors.lastname: Pálmai
authors.affiliation: Institute of Chemistry, Eötvös Loránd University, H-1117 Budapest, Pázmány Páter sétány 1/A., Hungary.
authors.forename: Roland
authors.initials: R
authors.lastname: Szalay
authors.affiliation: LGC Limited, Queens Road, Teddington, Middlesex TW11 0LY, UK.
authors.forename: Dorota
authors.initials: D
authors.lastname: Bartczak
authors.affiliation: Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences (IMEC RCNS HAS), H-1117 Budapest, Magyar Tudósok körútja 2., Hungary. Electronic address: varga.zoltan@ttk.mta.hu.
authors.forename: Zoltán
authors.initials: Z
authors.lastname: Varga
authors.affiliation: Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences (IMEC RCNS HAS), H-1117 Budapest, Magyar Tudósok körútja 2., Hungary.
authors.forename: Lívia Naszályi
authors.initials: LN
authors.lastname: Nagy
authors.affiliation: Physikalisch-Technische Bundesanstalt (PTB), Abbestr. 2-12, 10587 Berlin, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Gollwitzer
authors.affiliation: Physikalisch-Technische Bundesanstalt (PTB), Abbestr. 2-12, 10587 Berlin, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Krumrey
authors.affiliation: LGC Limited, Queens Road, Teddington, Middlesex TW11 0LY, UK.
authors.forename: Heidi
authors.initials: H
authors.lastname: Goenaga-Infante
mesh_terms: D002712:Chlorides / Q000737:chemistry; D031521:Fractionation, Field Flow; D007201:Indicator Dilution Techniques; D007554:Isotopes / Q000737:chemistry; D013058:Mass Spectrometry; D053758:Nanoparticles / Q000032:analysis*; D053838:Scattering, Small Angle; D012821:Silanes / Q000737:chemistry; D012825:Silicon / Q000737:chemistry*; D017655:Silicon Compounds / Q000737:chemistry; D012822:Silicon Dioxide / Q000032:analysis*; D014961:X-Ray Diffraction
chemical_list: D002712:Chlorides; D007554:Isotopes; D012821:Silanes; D017655:Silicon Compounds; C040733:tetraethoxysilane; D012822:Silicon Dioxide; C039676:silicon tetrachloride; D012825:Silicon
keywords: Asymmetric flow field-flow fractionation (AF4); ICP-MS; SAXS; Si-29 silica nanoparticles; Si-29 tetraethyl orthosilicate