Physicochemical characterization of titanium dioxide pigments using various techniques for size determination and asymmetric flow field flow fractionation hyphenated with inductively coupled plasma mass spectrometry

Autor(en)

Johannes P. F. G. Helsper, Ruud J. B. Peters, Margaretha E. M. van Bemmel, Zahira E. Herrera Rivera, Stephan Wagner, Frank von der Kammer, Peter C. Tromp, Thilo Hofmann, Stefan Weigel

Abstrakt

Seven commercial titanium dioxide pigments and two other well-defined TiO

₂ materials (TiMs) were physicochemically characterised using asymmetric flow field flow fractionation (aF4) for separation, various techniques to determine size distribution and inductively coupled plasma mass spectrometry (ICPMS) for chemical characterization. The aF4-ICPMS conditions were optimised and validated for linearity, limit of detection, recovery, repeatability and reproducibility, all indicating good performance. Multi-element detection with aF4-ICPMS showed that some commercial pigments contained zirconium co-eluting with titanium in aF4. The other two TiMs, NM103 and NM104, contained aluminium as integral part of the titanium peak eluting in aF4. The materials were characterised using various size determination techniques: retention time in aF4, aF4 hyphenated with multi-angle laser light spectrometry (MALS), single particle ICPMS (spICPMS), scanning electron microscopy (SEM) and particle tracking analysis (PTA). PTA appeared inappropriate. For the other techniques, size distribution patterns were quite similar, i.e. high polydispersity with diameters from 20 to >700 nm, a modal peak between 200 and 500 nm and a shoulder at 600 nm. Number-based size distribution techniques as spICPMS and SEM showed smaller modal diameters than aF4-UV, from which mass-based diameters are calculated. With aF4-MALS calculated, light-scattering-based “diameters of gyration” (Øg) are similar to hydrodynamic diameters (Øh) from aF4-UV analyses and diameters observed with SEM, but much larger than with spICPMS. A Øg/Øh ratio of about 1 indicates that the TiMs are oblate spheres or fractal aggregates. SEM observations confirm the latter structure. The rationale for differences in modal peak diameter is discussed.

Organisation(en)

Externe Organisation(en)

Wageningen University and Research Centre, Netherlands Organisation for Applied Scientific Research, Bundesinstitut für Risikobewertung, Helmholtz-Zentrum für Umweltforschung

Journal

Analytical and Bioanalytical Chemistry

Band

408

Seiten

6679-6691

Anzahl der Seiten

13

ISSN

1618-2642

DOI

https://doi.org/10.1007/s00216-016-9783-6

Publikationsdatum

09-2016

Peer-reviewed

Ja

ÖFOS 2012

210001 Nanoanalytik, 104023 Umweltchemie, 104002 Analytische Chemie, 105906 Umweltgeowissenschaften

Schlagwörter

ASJC Scopus Sachgebiete

Analytical Chemistry, Biochemistry

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/e1a9940b-4629-4971-95db-658ba70bbba5