What is microwave digestion?
Microwave digestion is a technique that is achieved by subjecting a sample to a strong acid in a closed vessel followed by an increase in pressure and temperature through microwave irradiation.
The rapid pressure and temperature increase causes the sample to break down much faster than traditional methods like an oven or a simple acid or alkaline digest. The increase in pressure and temperature of the acidic sample amplifies both the speed of thermal decomposition of the sample as well as the solubility of metal elements in solution.
Once the samples are in solution, it is possible to quantify the metal elements by ICP-MS analysis.
What are the benefits of using microwave digestion, and what equipment is available to do it?
At Arcinova, A Quotient Sciences Company, our facility in Alnwick, UK has an ultraWAVE digester that has been used successfully in many regulated studies for the digestion of complex biological matrices and elements.
The use of the ultraWAVE digester is less labor intensive. An alternative approach is an overnight digest in a concentrated acid which takes more time for the analyst to set up and digest. This digest occurs overnight whereas the ultraWAVE digester cycle lasts approximately 30 minutes from start to finish.
This process can be done in much less time due to a few reasons:
- Sample rack inserts can hold up to 26 samples that are all digested simultaneously in one cycle
- Disposable vials are used to contain the sample when in the digester, for no additional cleaning step between cycles and no carryover observed.
- Different biological matrices can be digested together, and difficult matrices can also be digested. For example, bones and nails.
Due to the benefits listed, we often see an increased sample throughput when using the ultraWAVE digester compared to alternative approaches.
Has Arcinova used the ultraWAVE Digester for regulated studies?
The ultraWAVE digester has been used for validation work and regulated sample analysis studies.
In one study, the digester was used during a GLP study in which our team analyzed over 600 tissue samples. The team digested and analyzed bone marrow, brain, GI tract, liver, ovaries, testes, spleen and uterus tissue samples.
In what situations does Arcinova recommend using the ultraWAVE Digester?
The alternative approach to using the ultraWAVE Digester is an overnight digest in a concentrated acid or base—which is labor intensive and takes time. Depending on the sample, an acid/base digest can also take longer than overnight, causing delays to sample analysis.
We recommend and frequently use the ultraWAVE digester, especially in cases involving:
- Metallic nanoparticle solids
- Challenging matrices such as bone that do not easily digest
- Large clinical and non-clinical studies that require analysis of a vast amount of samples
- Clinical and non-clinical studies that have more than one tissue type requiring digest
The ultraWAVE digester is a patented technology under Milestone.