Four acid digestions

Advantages of four-acid decomposition

Multi-acid methods such as ALS’s four-acid are popular due to demonstrated utility. Defining the value of a resource project goes beyond determining the contained volume of metal. Four-acid digestion methods offered by ALS provide data that can be used to estimate mineralogy and establish proxies for physical and chemical deposit characteristics such as the hardness of ore, deleterious gangue mineralogy, weathering and oxidation fronts, identification of construction materials such as road base and mapping of reactive sulphides for acid mine drainage management.

Digestão de quatro ácidos

Super trace four-acid digestion

Our ME-MS61L™ method provides robust results at levels well below the lowest regional backgrounds for most elements, allowing an unprecedented level of detail in major and trace element geochemistry on every sample.


Method - ME-MS61L™

This method provides ALS's lowest detection levels from a four-acid digestion and is achieved via proprietary ICP-MS methodology.

Code Analytes & Ranges (ppm)
ME-MS61L™
0.25g sample 		Ag 0.002-100 Cu 0.02-10,000 Na 0.001%-10% Sr 0.02-10,000
Al 0.01%-50% Fe 0.002%-50% Nb 0.005-500 Ta 0.01-500
As 0.02-10,000 Ga 0.05-10,000 Ni 0.08-10,000 Te 0.005-500
Ba 1-10,000 Ge 0.05-500 P 0.001%-1% Th 0.004-10,000
Be 0.02-1,000 Hf 0.004-500 Pb 0.01-10,000 Ti 0.001%-10%
Bi 0.002-10,000 In 0.005-500 Rb 0.02-10,000 Tl 0.002-10,000
Ca 0.01%-50% K 0.01%-10% Re 0.0004-50 U 0.01-10,000
Cd 0.005-1,000 La 0.005-10,000 S 0.01%-10% V 0.1-10,000
Ce 0.01-500 Li 0.2-10,000 Sb 0.02-10,000 W 0.008-10,000
Co 0.005-10,000 Mg 0.01%-50% Sc 0.01-10,000 Y 0.01-500
Cr 0.3-10,000 Mn 0.2-100,000 Se 0.006-1000 Zn 0.2-10,000
Cs 0.01-500 Mo 0.02-10,000 Sn 0.02-500 Zr 0.1-500

Rare earth elements and lead isotope analysis

A full suite of Rare Earth Elements (REEs) can be added to the ME-MS61L™ method as well as Pb isotope analysis. These add-on methods can provide useful information for exploration in some regions and deposit types. Depending on the minerals hosting the REEs the digestion may not be complete which will provide only the REEs hosted in the labile minerals and adsorbed to mineral surfaces.


Add on methods - MS61L-REE™ & MS61L-PbIS™

REEs and/or Pb isotope measurements can be added to ME-MS61L™ to provide extra dimension for exploration.

Code Analytes & Ranges (ppm)
MS61L-REE™
Add-on only 		Dy 0.005-1000 Ho 0.002-1000 Sm 0.004-1000
Er 0.004-1000 Lu 0.002-1000 Tb 0.002-1000
Eu 0.004-1000 Nd 0.005-1000 Tm 0.002-1000
Gd 0.005-1000 Pr 0.004-1000 Yb 0.004-1000
MS61L-PbIS™
Add-on only 		204Pb 0.01-10000 207Pb 0.01-10000
206Pb 0.01-10000 208Pb 0.01-10000

Frequently asked questions

  • Is four-acid digestion a total decomposition?

    No. Some resistive minerals are only partially broken down by a 4-acid digestion and the extent of digestion is often due to the form they take. For example, a zircon that has no structural damage will be highly resistant to 4-acid digestion but zircon that is metamict will often be digested due to structural damage in the mineral.

Related resources

Análise de metais básicos

Alternative detection limits

When super trace detection limits are not needed, four-acid methods with alternative detection limits are available.

MORE INFORMATION

Downloads

pdf

ALS 4 Acid Digest & Advanced ICP-MS Technical Note

pdf

ALS Pb Isotope Ratios

pdf

ALS Aqua Regia or Four Acid Technical Note

22 JUN 2022

pdf

ALS Super Trace Methods Tech Note (Rev1.0)