Nano-Pellets as reference materialsWednesday, September 4, 2019
The idea to press powders into pellets is not new. Until now it has been necessary to add a binding agent to the form stable pellets. This dilutes the sample and changes the sample-matrix. The innovation behind the nano-pellets is grinding the powders to a grain-size of D50 of 200 nm (50 % of the powder is ≤ 200 nm) and subsequently pressing them with an extremely smooth surface (Ra 24 nm, roughness parameter).
Due to the fine particle size interparticular cohesion increases, thus increasing stability. The lack of binder allows undiluted and truly matrix-matched analysis. The white material surrounding the pellets is merely a fortification for increased stability and improved handling.
Further, the small particle-size allows stoichiometric analysis even at small spot-sizes.
Use of reference materials
In order to properly apply RMs, the Joint Research Centre (JRC) of the European Commission has published Application Notes. Among other things they show standard practises for statiscally comparing the measured and certified value.