SELF TEST 4.2

Minerals in the clays

Resins in the varnishes

Binders in the paints

Crystalline pigments in the paints

Amorphous pigments in the papers

Cellulose-based fibres in the textiles

In ED-XRF, all the emitted fluorescence radiation reaches the detector at once; in WD-XRF, the detector detects all the fluorescent X-rays element by element

WD-XRF uses pulse-height discriminator to electronically classify the results; ED-XRF does not have an automatic classifier

In WD-XRF, all the emitted fluorescence radiation reaches the detector at once; in ED-XRF, the detector detects all the fluorescent X-rays element by element

ED-XRF uses pulse-height discriminator to electronically classify the results; WD-XRF does not have an automatic classifier

Mineralogy effects are eliminated

Less material is needed for sample preparation

The particle size effects are eliminated

The method is relatively easy

Can’t detect carbon in the sample

For the quantitative analysis, minimum of 1 g sample powder is needed

Impossible to analyse directly amorpheous materials

Can’t detect lighter elements than aluminium

 … measuring crystalline structure of the sample

… quantitative analysis and for that only 1 mg of sample is needed

… measuring diffraction angles and the intensities of diffraction peaks

 … determining bond types in the samples

XRD and XRF can be used to identify liquid materials

XRD can be used to determine elemental composition of the sample

XRF can be used to determine the structure of crystalline materials

XRD can be used to identify crystalline materials

XRF can be used to determine elemental composition of the sample

XRD can be used to identify amorphous materials

Large database of known crystalline structures

Possibility to perform accurate quantitative analysis

Possibility to perform in-situ analyses

Elemental mapping possibility

Fast elemental analysis

No sample preparation

Computer-aided material identification

Cost-effective

Analysis of XRD patterns is complicated and is typically done by a specialist

It is possible to determine which crystalline phases are in a mixture

It is possible to identify all the inorganic and organic materials

It is possible to determine if amorphous material is present in the mixture

For the interpretation, library of known crystalline structures is used

Interpretation of XRD diffractogram is easier compared to the interpretation of WD-XRF spectrum

Enables direct analysis from the object surface

Non-destructive

A cross-section of the paint sample can be analysed

Easy to use

No sample preparation needed

Cost-effective

Computer-aided material identification

Ground samples needed for quantitative analysis