ISO 18227:2014

INTERNATIONAL ISO
STANDARD 18227
First edition
2014-03-01
Soil quality — Determination of
elemental composition by X-ray
fluorescence
Qualité du sol — Détermination de la composition élémentaire par
fluorescence X
Reference number
©
ISO 2014
© ISO 2014
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ii © ISO 2014 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Safety remarks . 3
5 Principle . 3
6 Apparatus . 3
7 Reagents . 4
8 Interferences and sources of error . 5
9 Sample preparation . 5
9.1 General . 5
9.2 Drying and determination of dry mass . 6
9.3 Preparation of pressed pellet . 6
9.4 Preparation of fused beads . 6
10 Procedure. 7
10.1 Analytical measurement conditions . 7
10.2 Calibration . 8
11 Quality control .13
11.1 Drift correction procedure .13
11.2 Blank test .14
11.3 Reference materials .14
12 Calculation of the result .14
13 Test report .14
Annex A (informative) Semi-quantitative screening analysis of waste, sludge, and soil samples .15
Annex B (informative) Examples for operational steps of the sample preparation for soil and
waste samples .18
Annex C (informative) Suggested analytical lines, crystals, and operating conditions .23
Annex D (informative) List of reference materials applicable for XRF analysis .26
Annex E (informative) Validation .28
Bibliography .37
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
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The committee responsible for this document is ISO/TC 190, Soil quality, Subcommittee SC 3, Chemical
methods and soil characteristics.
iv © ISO 2014 – All rights reserved

Introduction
X-ray fluorescence spectrometry is a fast and reliable method for the quantitative analysis of the total
content of certain elements within different matrices.
The quality of the results obtained depends very closely on the type of instrument used, e.g. bench top or
high performance, energy dispersive or wavelength dispersive instruments. When selecting a specific
instrument, several factors have to be considered, such as the matrices to be analysed, the elements
to be determined, the detection limits required, and the measuring times. The quality of the results
depends on the element to be determined and on the surrounding matrix.
Due to the wide range of matrix compositions and the lack of suitable reference materials in the case
of inhomogeneous matrices such as waste, it is generally difficult to set up a calibration with matrix-
matched reference materials.
Therefore, this International Standard describes two different procedures:
— a quantitative analytical procedure for homogeneous solid waste, soil, and soil-like material in the
normative part. The calibration is based on matrix-matched standards;
— an XRF screening method for solid and liquid materials as waste, sludge, and soil in Annex A which
provides a total element characterization at a semi-quantitative level. The calibration is based on
matrix-independent calibration curves, previously set up by the manufacturer.
The technical content of this International Standard is identical with the European Standard
EN 15309:2007.
INTERNATIONAL STANDARD ISO 18227:2014(E)
Soil quality — Determination of elemental composition by
X-ray fluorescence
1 Scope
This International Standard specifies the procedure for a quantitative determination of major and trace
element concentrations in homogeneous solid waste, soil, and soil-like material by energy dispersive
X-ray fluorescence (EDXRF) spectrometry or wavelength dispersive X-ray fluorescence (WDXRF)
spectrometry using a calibration with matrix-matched standards.
This International Standard is applicable for the following elements: Na, Mg, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr,
Mn, Fe, Co, Ni, Cu, Zn, As, Se, Br, Rb, Sr, Y, Zr, Nb, Mo, Ag, Cd, Sn, Sb, Te, I, Cs, Ba, Ta, W, Hg, Tl, Pb, Bi, Th,
and U. Concentration levels between approximately 0,000 1 % and 100 % can be determined depending
on the element and the instrument used.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO 11464, Soil quality — Pretreatment of samples for physico-chemical analysis
ISO 11465, Soil quality — Determination of dry matter and water content on a mass basis — Gravimetric
method
ISO/IEC 17025, General requirements for the competence of testing and calibration laboratories
EN 14346:2006, Characterization of waste — Calculation of dry matter by determination of dry residue or
water content
EN 15002:2006, Characterization of waste — Preparation of test portions from the laboratory sample
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
NOTE See References [11] and [14] for non-specified terms.
3.1
absorption edge
jump of the mass absorption coefficient at a specific wavelength or energy
3.2
absorption of X-rays
loss of intensity of X-rays by an isotropic and homogenous material as described by the Bouger-Lambert
law
3.3
analytical line
specific characteristic X-ray spectral line of the atom or ion of the analyte used for the determination of
the analyte content
3.4
continuous radiation
electromagnetic radiation produced by the acceleration of a charged particle, such as an electron, when
deflected by another charged particle, such as an atomic nucleus
3.5
Compton-line
spectral line due to incoherent scattering (Compton-effect) occurring when the incident X-ray photon
strike an atom without promoting fluorescence
Note 1 to entry: Energy is lost in the collision and therefore the resulting scattered X-ray photon is of lower energy
than the incident X-ray photon.
3.6
drift correction monitor
physically stable sample used to correct for instrumental drift
3.7
emitted sample X-ray
radiation emitted by a sample consisting of X-ray fluorescence radiation and scattered primary X-rays
3.8
fused bead
analyte sample prepared by dissolution in a flux
3.9
liquid sample
analyte sample submitted as a solution for direct measurement in the sample cup
3.10
mass absorption coefficient
constant describing the fractional decrease in the intensity of a beam of X-radiation as it passes through
an absorbing medium
Note 1 to entry: This is expressed in cm /g.
Note 2 to entry: The mass absorption coefficient is a function of the wavelength of the absorbed radiation and the
atomic number of the absorbing element.
3.11
polarized excitation X-ray spectrometer
energy dispersive X-ray spectrometer where the excitation is performed by polarized radiation and the
emitted X-ray fluorescence radiation is detected along the direction of polarization
3.12
powder sample
analyte sample submitted as a powder for direct measurement in the sample cu
...