SELF TEST 4.2

Minerals in the clays

Amorphous pigments in the papers

Cellulose-based fibres in the textiles

Binders in the paints

Resins in the varnishes

Crystalline pigments in the paints

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

Can’t detect carbon in the sample

Can’t detect lighter elements than aluminium

Impossible to analyse directly amorpheous materials

ED-XRF uses pulse-height discriminator to electronically classify the results; WD-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

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

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

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

 … determining bond types in the samples

 … measuring crystalline structure of the sample

… measuring diffraction angles and the intensities of diffraction peaks

Cost-effective

Large database of known crystalline structures

Possibility to perform accurate quantitative analysis

Possibility to perform in-situ analyses

Elemental mapping possibility

No sample preparation

Fast elemental analysis

Computer-aided material identification

XRF can be used to determine the structure of crystalline materials

XRD can be used to identify amorphous materials

XRD can be used to identify crystalline materials

XRF can be used to determine elemental composition of the sample

XRD and XRF can be used to identify liquid materials

XRD can be used to determine elemental composition of the sample

The particle size effects are eliminated

The method is relatively easy

Mineralogy effects are eliminated

Less material is needed for sample preparation

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

It is possible to identify all the inorganic and organic materials

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

Ground samples needed for quantitative analysis

Enables direct analysis from the object surface

Cost-effective

Computer-aided material identification

Easy to use

A cross-section of the paint sample can be analysed

Non-destructive

No sample preparation needed