Hi All,
We are trying to add Magnesium & Strontium dopants to our Beta Tricalcium Phosphate (b-TCP) powder. Recently, we obtained EDS data on the undoped b-TCP and doped b-TCP to see if the investigate if the doping was successful. However, we are observing higher weight percentages of the Magnesium dopant in the undoped b-TCP and we can't figure out why we are observing this trend. After we first observed this, we have used EDS to look at multiple different samples but they are all showing similar results. We have contacted the manufacturer of the pure, undoped, b-TCP powder and they agree that we should not be seeing this. We are pretty confident that we don't have contaminated, undoped, pure b-TCP powder. But we still aren't sure what might be causing these results. The attached Mg Map Data is from the undoped b-TCP only but the spreadsheet shows some examples of the weight% values we are observing.
Does anyone have any ideas that might explain the results? Are there any recommendations for how we can discriminate between potentially overlapping signals that might be giving false Mg signals?
Thanks!
Dear Genesis Marrero ,
please forget about those ugly very low numbers of % and even the variation of these numbers in your maps.
To my opinion you only 'see' the noise in the background of your EDS spectra around the energy position the Mg K-alphas ( ~1,25keV) and the Sr L-alphas (~1,8keV). Your software may identify accidental noise peaks as real ones.
The operator of your system should know about such issue.
You may share some typical measured spectra; so we will have an impression on the quality of the statistical noise or even of peak overlapings in these regions.
Many thanks in advance
and best regards
G.M.
I fully agree with Gerhard Martens . I too would like to see raw data (spectra). It would give some idea about quality of acquisition. You are trying to work at the very limit of possibilities of EDS, and I am afraid an EDS operator is not up to the task (otherwise the useless maps would not be presented).
I recall EDS is a bit complicated when there are several peaks of different elements close together. If you at working at the limit of detection as Gerhard Martens and Vladimir Dusevich are suggesting, random noise may look like a peak of Mg, or it might be the adjacent element.
If you do some back-of-the-envelope calculations, you should be able to estimate the approximate Mg concentration of the doped sample. If this is less than the LOD of the EDS detector you are using, then you will not see a positive result regardless of the success of the doping procedure.
I would suggest testing with another technique (I favour ICP-MS, but there are others). If that doesn't show a positive response, maybe your doping procedure is off in some way.
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