Whole rock analytical methods are required when lithogeochemical classification by geochemistry will be applied. Whole rock methods all involve a fusion decomposition that breaks down all minerals in the sample, therefore liberating all elements for analysis. Also, methods for the major rock forming element determinations do not use hydrofluoric acid that volatises Si as SiF4 so that silicon can be reported.
Both XRF and ICP-AES instruments can be utilised to determine the major rock-forming elements following a lithium borate fusion. These methods are not suitable for samples with base or precious metals mineralisation. Specific commodities such as iron ore, bauxite, and base metal sulphides should be analysed with methods designed for those sample types as the flux and instrument calibration are optimised for them.
ALS offers method ME-XRF26 which is an XRF measurement on a fused disc. Alternatively, an ICP-AES measurement method on a fused sample is an option by ME-ICP06. With XRF analysis the fused disc is analysed directly by the instrument, however, when measuring a fused sample by ICP-AES, there is an extra digestion step required to dissolve the fused sample for introduction to the ICP-AES as a solution.
Code | Analytes and ranges (%) | Description | |||||||
---|---|---|---|---|---|---|---|---|---|
ME_XRF26* 2g sample |
Al2O3 | 0.01-100 | Fe2O3 | 0.01-100 | Na2O | 0.01-10 | SrO | 0.01-1.5 | Fused disc XRF,
LOI by furnace or TGA |
BaO | 0.01-66 | K2O | 0.01-15 | P2O5 | 0.01-46 | TiO2 | 0.01-30 | ||
CaO | 0.01-60 | MgO | 0.01-50 | SO3 | 0.01-34 | LOI | 0.01-100 | ||
Cr2O3 | 0.01-10 | MnO | 0.01-39 | SiO2 | 0.01-100 |
Code | Analytes and ranges (%) | Description | |||||||
---|---|---|---|---|---|---|---|---|---|
ME_ICP06* 2g sample |
Al2O3 | 0.01-100 | Fe2O3 | 0.01-100 | Na2O | 0.01-100 | TiO2 | 0.01-100 | Fused bead, acid digestion and ICP-AES. LOI by furnace or TGA |
BaO | 0.01-100 | K2O | 0.01-100 | P2O5 | 0.01-100 | LOI | 0.01-100 | ||
CaO | 0.01-100 | MgO | 0.01-100 | SiO2 | 0.01-100 | ||||
Cr2O3 | 0.002-100 | MnO | 0.01-100 | SrO | 0.01-100 |
Fusion with lithium borate flux followed by acid dissolution of the fused bead coupled with ICP-MS analysis provides a quantitative analytical approach for a broad suite of trace elements. To this, whole rock analytes may be added by analysing the same digested solution by ICP-AES, or base metals from a separate four-acid digestion and ICP-AES.
ALS offers method ME-MS81™ to determine trace elements from a fused sample with ICP- MS instrument analysis. To add a whole rock analysis (ME-ICP06) to the trace elements (ME- MS81™) an economical package ME-MS81d is available. There is also an option to add base metals from a four-acid digestion by requesting ME-4ACD81.
Code | Analytes and ranges (ppm) | Description | |||||||
---|---|---|---|---|---|---|---|---|---|
ME-MS81™ 2g sample |
Ba | 0.5-10,000 | Hf | 0.1-10,000 | Sn | 1-10,000 | Y | 0.1-10,000 | Fused bead, acid digestion and ICP-MS |
Ce | 0.1-10,000 | Ho | 0.01-1,000 | Sr | 0.1-10,000 | Yb | 0.03-1,000 | ||
Cr | 10-10,000 | La | 0.1-10,000 | Ta | 0.1-2,500 | Zr | 2-10,000 | ||
Cs | 0.01-10,000 | Lu | 0.01-1,000 | Tb | 0.01-1,000 | ||||
Dy | 0.05-1,000 | Nb | 0.1-2,500 | Th | 0.05-1,000 | ||||
Er | 0.03-1,000 | Nd | 0.1-10,000 | Tm | 0.01-1,000 | ||||
Eu | 0.02-1,000 | Pr | 0.02-1,000 | U | 0.05-1,000 | ||||
Ga | 0.1-1,000 | Rb | 0.2-10,000 | V | 5-10,000 | ||||
Gd | 0.05-1,000 | Sm | 0.03-1,000 | W | 1-10,000 |
To set up an account you will need to contact our client services team. They can be messaged using the link on this page or you can call or email your local ALS Geochemistry client services representatives. Contact information is listed in the back of our fee schedule which can be downloaded from this site, or from the site locator.
There is no single analytical method that can determine all elements in a rock. ALS offers packages for complete characterisation.
MORE INFORMATIONWhen low detection levels are needed for trace elements, method ME-MS89L™ may be useful.
MORE INFORMATION