Hi all, I'm planning to measure the oxygen dissolved in Cu matte (Cu-Fe-S). The oxygen concentration would be in the range between 0.1 to 1.5wt%. And I'm looking for a secondary standard with similar amount of oxygen in there. Been going through NIST website, the closest one would be synthetic Cu2O (about 10wt% O)...also found some steel standards with only trace amount of oxygen (<100ppm). Haven't come across anything in between.
Suggestions are appreciated!!! ![Smiley :)](https://probesoftware.com/smf/Smileys/default/smiley.gif)
Hi Jeff,
I assume you want this secondary std to check the accuracy of measuring trace oxygen in Cu-Fe sulfides (matte?)? Are you attempting to characterize the oxidation state of the sulfur in that setting? It's a tough question for sure.
I suspect your best bet, considering the general relative lack of low level oxygen standards, would be to obtain some CuFe2 and/or FeS2 single crystals which one might have confidence (for reasons of synthetic purity or thermodynamic considerations perhaps?) that because they are perfect crystals and give a proper XRD patterns, therefore they might be oxygen free?
I have some vacuum remelted Fe metal that is stated to have 310 PPM of oxygen and 10 PPM of N, but of course besides being a very different matrix, the problem is surface oxidation for pure Fe...
Can anyone say whether synthetic (or natural for that matter!), simple sulfides should be essentially oxygen free to EPMA sensitivity levels?
john