This work describes the approach used to validate a method on the use of energy-dispersive X-ray fluorescence (ED-XRF) which should serve the purpose of analysing routinely trace elements in organic and inorganic matrices in a wide range of mass fractions. The following performance characteristics were determined: limit of quantification (LoQ), repeatability, intermediate precision, standard uncertainty, trueness, working range and robustness; matrix effect and selectivity were also evaluated. The method was applied to the determination of 25 elements (Al, As, Ba, Br, Ca, Cd, Cl, Cr, Cu, Fe, Hg, K, Mg, Mn, Mo, Ni, P, Pb, Rb, S, Se, Sr, Ti, Zn, Zr), in organic matrices and 12 elements (As, Br, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se, Zn,) in inorganic matrices and for mass fractions ranging from sub mg kg-1 level up to percentages, depending on the specific element.
The LoQ was empirically calculated as the mass fraction for which a certain trueness and uncertainty was achieved, on the basis of information gathered from the ratios between the calculated and the certified or reference mass fractions (Ccalc/CCRM) in the calibration curves. The lowest LoQ, 0.16 mg kg-1 was achieved for Ni. Trueness was evaluated using 29 certified reference materials (CRMs) and reference materials (RMs). Repeatability and intermediate precision was found to be mass fraction-related, the higher the mass fraction the larger the repeatability/intermediate precision.
The method was satisfactorily applied to the determination of trace elements in sediments, soils, cereals (wheat and rice), tobacco, feed, fish and milk.
FIAMEGKOS Ioannis;
DE LA CALLE GUNTINAS Maria Beatriz;
2019-01-25
PERGAMON-ELSEVIER SCIENCE LTD
JRC112597
0584-8547 (online),
www.elsevier.com/locate/sab,
https://publications.jrc.ec.europa.eu/repository/handle/JRC112597,
10.1016/j.sab.2018.10.009 (online),
