XRF Semi-Quantitative Analysis

Examples of semiquantitative (SQX) XRF analyses are shown below. These examples represent a variety of reference materials prepared using both pressed powders and fused glass disks. For a comparison of XRF Semi-Quantitative Analysis and ICPMS, click here.

E-Glass Standard

Thin film on top of paraffin

	Wt%
	Certified	Observed
SiO₂	54.53	55
CaO	17.43	21
Al₂O₃	14.62	16
MgO	4.67	6.3
Fe₂O₃	0.42	0.55
Na₂O	0.22	0.33
TiO₂	0.23	0.33
ZrO₂	0.12	0.02
Cr₂O₃	0.019	0.014
Date Analyzed:	8-7-2003

Even thin films of small samples (5-100 mg) can give excellent results as shown in the first example. This sample was a powdered glass mounted as a thin film on top of pressed paraffin.

In this example, NIST SRM 679 Brick Clay was fused with lithium tetraborate to form a fused glass disk.

SRM 679 Brick Clay

Lithium tetraborate fusion

	Wt%
	Certified	Observed
SiO₂	52.03	55
Al₂O₃	20.81	22
Fe₂O₃	12.94	14
K₂O	2.93	3.4
MgO	1.25	1.5
TiO₂	0.962	1.1
Na₂O	0.176	0.66
MnO	0.223	0.39
CaO	0.228	0.33
P₂O₅	0.172	0.18
Cr₂O₃	0.016	0.028
ZnO	0.0187	0.017
SrO	0.0087	0.011
Date Analyzed:	8-27-2003

Automatic Sample Changer

Rigaku ZSX100e

In these next two examples, the reference materials were mixed with an organic binder and pressed into pellets for analysis.

SRM 77 Bauxite
Pressed power pellet

	Wt%
	Certified	Observed
Al2O3	59.4	57
SiO2	32.4	33
TiO2	2.9	3.2
Fe2O3	0.9	2.1
ZrO2	0.09	0.085
Date Analyzed:	9-30-2003

SRM 88 Dolomite Limestone
Pressed powder pellet

	Wt%
	Certified	Observed
CaO	30.5	35
MgO	21.5	27
SiO₂	0.31	0.33
Al₂O₃	0.067	0.26
SO₃	0.05	0.09
Na₂O	0.08	0.045
K₂O	0.03	0.023
MnO	0.006	0.013
P₂O₅	0.003	0.008
SrO	<0.01	0.008
Date Analyzed:	9-30-2003

Conclusions:

XRF produces excellent Semi-Quantitative (SQX) Results
XRF SQX range is ~0.01%-100%
XRF is for solids while samples for ICP-MS must be dissolved