dc.description.abstract
Aluminosilicates are the most abundant minerals on the earth and are widely studied and
exploited for both research and industrial purposes. Together with mineralogical and physical
investigations, chemical analysis of aluminosilicates is a crucial step in their study and
characterization. Due to their abundance, sample procurement is not a problem and elemental
analysis is usually performed by ICP-AES, ICP-MS, after complete mineralization of the
sample, or by EDXRF and WDXRF, using 1-5 g of material. However, in some fields of
research (i.e. ceramic archaeometry, material synthesis, catalysis, sorption studies, clays
extraction from sediments and soils, etc.) only a very few amount of sample is usually available,
and a method which could allow a reliable chemical analysis and preserve the sample as much
as possible is required. A method for the elemental analysis of clays using TXRF was already
developed[1] but light elements like Na and Mg could not be quantified due to the limitations
of commercially available spectrometers for the analysis of light elements. However, the
quantification of these two elements is very important for an exhaustive chemical
characterization of aluminosilicates.
For this reason, in the present work, a new strategy for the analysis of light elements in
aluminosilicates is presented. The study was carried out using a Low-Z TXRF spectrometer [2]
equipped with a Cr source (30 kV, 10 mA), an Atominstitut TXRF Vacuum Chamber (1 mbar),
a W/C multilayer monochromator and a SDD with an ultrathin Si3N4 window[3]. A set of six
different aluminosilicate-rock reference materials was used for calibration and other three
reference materials were used for validation. Samples were prepared as suspension using Ag as
internal standard. In this way, all the elements from F to Ti were detected and quantified with
good accuracy (80-120%). Moreover, Fe was also quantified using Lα lines. The obtained
results will be discussed on both the analytical and applicative point of view, with the aim of
identifying the best equipment and condition for a full elemental characterization of
aluminosilicates.
[1] I. Allegretta, B. Ciasca, M.D.R. Pizzigallo, V.M.T. Lattanzio, R. Terzano, Applied Clay Science 180, 2019,
105201.
[2] S. Sasamori, F. Meirer, N. Zoeger, C. Streli, P. Kregsamer, S. Smolek, C. Mantler, P. Wobrauschek, ECS
Transactions, 2009, 25, 301–309.
[3] https://www.amptek.com/products/x-ray-detectors/fastsdd-x-ray-detectors-for-xrf-eds/c-series-low-energy-x-
ray-windows
en