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The Joint Research Centre (JRC) is the European Commission's science and knowledge service which employs scientists to carry out research in order to provide independent scientific advice and support to EU policy.
Processing of candidate reference materials often includes a sieving step when manipulating powders. Due to an increasing demand from laboratories, more and more fat-rich and oily materials have to be processed into reference materials, especially in the GMO and mycotoxin fields. Generally,
sieving of fat-rich powders results in gradually blocked sieves and increased oil/fat release, and in the worst case, severe clogging.
JRC-IRMM experts tackled this problem by developing a method for cryogenic sieving using liquid nitrogen. This new approach made it possible to process the recently released certified reference material (CRM) ERM-BF434, the world-wide first CRM for a GMO rapeseed powder. The new method has the potential to be used for sieving of materials even if they are not “free flowing” at room-temperature, e.g. GMO rapeseed powders and pistachio powders.
Further refinements of a cryogenic sieving system are now being done in collaboration with a manufacturer of industrial sieves.
Example shown of sieving pistachio powder at room temperature resulting in severely clogged screen.
|Example shown of sieving|
pistachio powder at room
in severely clogged screen.
The same screen is shown after cold-sieving of pistachio powder without clogging.
|The same screen is shown after|
cold-sieving of pistachio
powder without clogging.