Dear Sir, Our laboratory is adopting ICP-OES analysis of cement by borate fusion as an alternative to ASTM C114 reference method and XRF. We are using 0.1g sample fused with 1.0g flux (Lithium Metaborate and/or Lithium Tetraboarate), ignited at 950degC and dissolved with 10% HCl. We are still validating the method. There are times when results for Cao and/or SiO2 are not favorable and results for Na2O and TiO2 are not good. Are you or you know a lab that has the same practice. Can you recommend some improvements? Inputs regarding this will be highly appreciated. I hope you could help me on this. Thanks, Aiyama
Benoit
Hello Aiyama,
I work with fusion on many different kind of materials everyday. With cement, I usually heard that people mainly use fusion beads for X-Ray analysis and it works perfectly. Making solutions by ICP as you make should not be a problem. The thing that catch my attention is the low amount of flux that you use. This low amount of flux can be problematic for the well mix between the flux and the sample. If the fusion mix is not well mixed or static during the fusion, this can have an influence on the dissolution of the sample in the flux. Do you shake your crucible during the fusion ? Do you use muffle furnace or automated fusion device ?
The dissolution of cement in lithium-borate flux is not a problem and has been demonstrated in many application notes. I pretty sure that the problem in your case is the physical disposition of the flux and sample. It's possible that you have incomplete dissolution of the sample in the flux and that brings you reproducibility problem.
Take a look at this and tell us if it make sens
Ben