To understand metals and determine metal quantities within various samples, chemists opt for a variety of analytical techniques. All of these methods rely on digestion to prepare the sample for analysis.
What is Metal Digestion?
The process of metal digestion is specific to the methods whereby samples are treated first to isolate metals of interest within a range of sample matrices. Critical applications in both commercial and regulatory environments, at high and low levels, require reproducible accuracy. Digestion analysis of metals will often affect decisions made within mining, environmental impact and quality assurance workflows in food and pharmaceutical production.
The analysis provides precise sample digestion, which can detect a wide variety of metals down to the part per trillion (ppt) range. Acids are the most common option for breaking down metal that contains compounds. Some of the more popular acids used include nitric acid, hydrochloric acid, perchloric acid, sulfuric acid, and hydrofluoric acid. These acids can be used in various combinations to digest numerous samples.
Microwave Digestion
Microwave digestion is a technique often used by elemental scientists when dissolving heavy metals in the presence of organic molecules. This happens before analysis by inductively coupled plasma, atomic absorption, or atomic emission measurements.
It works by exposing a sample to a strong acid (mentioned above) in a closed vessel. Next, the temperature and pressure are raised via microwave irradiation. This increases both the speed of thermal decomposition from the low pH sample and the solubility of heavy metals in the solution. Finally, once the heavy metals are in solution, you can then quantify the sample through elemental techniques.
Metal Digestion Equipment
At Delta, we stock metal digestion equipment for various application needs, for example:
- The Savillex Flat Inside Standard Outside Digestion Vessel, 120 mL - designed for rapid sample digestion via microwave techniques and rapid sample dissolution, with side ports for fluid or gas transfer.
- The Savillex Pressure Vessel, 2000 mL - a heavy-walled PFA pressure vessel designed for use in demanding pressure applications, with a variety of closures available.
- The Savillex Flat Inside and Outside Digestion Vessel, 60 mL - designed for rapid sample dissolution, includes a flat exterior for hot plate heating and digestion.
- The Savillex Conical Inside Cored Outside Digestion Vessel, 60 mL - designed for microwave rapid sample digestion and has a conical interior to aid in sample removal.
For more information about metal digestion or metal digestion equipment, please get in touch with the Delta team today and we’ll be happy to help. Alternatively, you can view more digestion equipment here.