The SEAL Analytical Block Digestion System is a heating block for laboratories available as a 50 place unit for 75ml or 100ml digestion tubes (BD50) or a 28 place unit for 250ml (BD28) digestion tubes.
System comprises:
- Heating block
- Microprocessor controller
- Tube rack/draft shield
- Set of digestion vessels
- Cooling stand that supports the tube rack above the block.
The overall unit has been designed for durability and robustness. The heating block has a stainless steel covering to provide a greater measure of acid resistance. Similarly, the tube rack and cooling stands are also manufactured from the highest quality stainless steel.
Comparison of a Block Digestion System to beakers on a hot plate
The SEAL Analytical BD50 and BD28 computer controlled heating blocks provides better quality results, higher productivity of sample throughput and uses less fume hood space per sample. It's also an automated process and frees the operator to perform other tasks. Digesting samples in a beaker on a hot plate requires constant vigilance and care. A Block Digestor allows you to digest 50 samples simultaneously with minimal operator supervision. All samples on the BD50 and BD28 heating blocks are processed at exactly the same temperature. Competing hot plates have hot and cold spots, and samples are often digested at different temperatures, giving inconsistent/ incorrect results. A SEAL computer controlled heating block regulates the exact digestion time and heating rates, whereas on a standard hot plate, the times are dependent upon an operator to remember to change the digest conditions.
Comparison of Block Digestion Systems to Microwave Digestion System
While microwave digestion systems can accelerate the digestion process, block digestion systems still offer a number of distinct advantages:
Larger runs- the SEAL BD28s and BD50s block digestion systems digest more samples and larger sample sizes in one batch. On a microwave digestion system, you are limited to 0.5g for inorganic samples, less for organic samples, the BD28s and BD50s allow you to use ten times this amount.
Less operator involvement- a microwave digestion system requires regular attention by the Operator, disassembling and reassembling digestion vessels. on the BD28s and BD50s, once you add samples and acid, digestion proceeds without intervention by the operator. The high operator involvement for the microwave digestion unit tends to negate the faster digestions.
More flexibility- It is possible to use a wider range of acids including sulphuric acid and perchloric acid on the BD28s and BD50s. On a microwave digestion system, sulphuric acid has too high a boiling point and will melt the PTFE vessels while perchloric acid can be explosive under pressure. It is not possible to perform kjeldahl digestions in a microwave system but you can on the BD28s and BD50s Block Digestion Systems.
Cost-The BD28s and BD50s Block Digestion Systems are much cheaper than microwave digestion systems, typically about a quarter of the cost. Microwave digestion systems also have on-going consumable costs, such as rupture membranes and digestion vessels have finite life. The BD28s and BD50s have no on-going consumable costs.
