Standardless XRF analysis of
jewelry and precious metal alloys.
Fields of
application
The procedure is developed
for jewelry analysis, precious metal scrap, technological alloys,
containing gold, silver or platinum, palladium, copper, zinc and nickel
without any standard samples.
The procedure is developed
for alloys containing not more than 5 elements of those listed above.
Errors of
measurements
Errors of
determination are not worse than those listed below within the
concentration range from 5 to 99.9
weight %.
Results
of standardless analysis of golden rings 583 and 375 assays
Concentration range, weight %.
Relative error %.
Element
Concentration
Element
Concentration
10 - 30
1 - 3
29 Cu
53.142
29 Cu
30.877
30 - 50
0.5 - 2
47 Ag
9.008
47 Ag
0.503
50 - 70
0.5 - 1
79 Au
37.850
79 Au
58.619
70 - 95
0.3 - 1
Sample preparation
Any samples
can be studied, though there are some limitations in size. Standard
instrument has a sample holder 40 mm in diameter and 40 mm high,
therefore a sample shall be within this size. Important - the sample
shall not be above the surface of the sample holder - not to damage the
instrument. Preferable to have surface close to flat, but it is not
obligatory. The surface of the sample shall be clean, area under
radiation shall be not less than 5 sq.mm.
Optionally - sample holder may be made to hold
samples up to 150x150x20 mm.