Digestion

Digestion is the conversion of a solid sample into a liquid, homogeneous state.
This makes the sample easier to aliquot and has all the prerequisites for an interference-free qualitative and quantitative determination of the elements or compounds of interest. 

After mechanical sample preparation, decomposition is the most time-consuming step in wet-chemical procedures. It is therefore very useful to optimize this step and reduce the required time while retaining or increasing the quality of the analysis.

Require-
ments
of the
digestion
procedure

• Exclusion of systematic errors by preventing
• Contamination 
• Loss of analytes
• Adsorption of analytes on the vessel surface
  
• The decomposition must be complete for the task in hand
  
• Removal of distorting matrices and prevention of matrix extension e.g. from the decomposition acids used
  
• Simple operation with minimum required time, work and instrument operation

All these requirements are fulfilled by a closed, microwave heated system.

Digestion
Agent

Prevention of contamination by the digestion agent
Contamination by the digestion agent can be prevented either by using purchased suprapur acids or purify p.a. acids by subboiling.

Vessels

Prevention of contamination by the vessels
The vessels can be cleaned by cleaning digestion or steaming equipment.

Vessel
Walls

Prevention of contamination by the vessel walls
Adsorption on the vessel walls is prevented by using highly pure materials which are chemically and thermally resistant, e.g. PFA, PTFE and quartz glass.