For high-throughput laboratories closed-vessel microwave digestion has some limitations.
The digestion vessels must be cleaned prior to each use (normally by a cleaning cycle in the microwave with an acid blank). The vessels must be assembled and disassembled, which is labor intensive, and the sample solution must be transferred to another container prior to analysis, which increases handling and contamination risk. The high temperature and pressure achieved during digestion degrade the vessels over time, resulting in significant consumables costs.
Finally, to ensure full control of the digestion run, the sample weight, matrix type, and acid used must be the same for every sample in the run. This means that a separate run must be performed for each sample type. High-throughput laboratories that have multiple sample types often employ several digestion systems.The Single Reaction Chamber (SRC) technology has none of the limitations of closed-vessel digestion, and has revolutionized digestion applications.
SRC microwave digestion was introduced commercially around ten years ago with ultraCLAVE.
The SRC is a new approach to microwave digestion. As its name suggests, the SRC is a large, pressurized stainless steel reaction chamber into which all samples are placed and digested simultaneously. With SRC, the reaction vessel in effect becomes the microwave cavity, enabling the intensity and distribution of the delivered microwave energy to be optimized to the shape of the reaction vessel. This ensures even heating and therefore eliminates the need to rotate samples during the digestion run. Because the samples are placed inside a pressurized vessel, individual pressure vessels are not needed.
Aside from the reduced handling and labor savings, a benefit of SRC over closed- vessel digestion is that it operates at very high temperature and pressure-up to 300 °C and 199 bar; thus complete digestion of even the most difficult sample tvpes is achieved. In addition, since all samples are in the same vessel, any combination of sample type (or weight) can be digested simultaneously.

Sample preparation is a central part of elemental analysis and includes several manual and time-consuming steps. Reagent addition into digestion vials or vessels is a tedious and often unpleasant process that, in high throughput labs, requires a significant amount of time.