4B1 - Total Digestion - ICP
A 0.25 g sample is digested with four acids beginning with hydrofluoric, followed by a mixture of nitric and perchloric acids, heated using precise programmer controlled heating in several ramping and holding cycles which takes the samples to dryness. After dryness is attained, samples are brought back into solution using hydrochloric acid. With this digestion certain phases may be only partially solubilized. These phases include zircon, monazite, sphene, gahnite, chromite, cassiterite, rutile and barite. Ag greater than 50 ppm and Pb greater than 5,000 ppm should be assayed as high levels may reprecipitate. Only sulphide sulfur will be solubilized.
In-lab standards (traceable to certified reference materials) or certified reference materials are used for quality control.
Samples are analyzed using a Varian Vista 735 ICP.
Option 4B1
Elements and Detection Limits (ppm)
|
Element
|
Detection Limit
|
Upper Limit
|
|
S
|
0.001%
|
20%
|
|
Ni
|
1
|
10,000
|
|
Zn
|
1
|
10,000
|
|
Cu
|
1
|
10,000
|
|
Cd
|
0.5
|
2,000
|
|
Ag
|
0.5
|
50
|
|
Pb
|
5
|
5,000
|
|