1
$\begingroup$

I have a mixture of metal oxides in powder form. Mainly Iron oxide, silicon dioxide, and calcium oxide. I know for certain calcium oxide is in the mixture, but my handheld XRF is not detecting it.

I am analyzing my sample through a very thin plastic wrap, polypropylene.

I have even taken a sample of pure lime, and my handheld XRF is not detecting any calcium. Just a bunch of others such as $\ce{Si, Al, P}$ and so on.

How might this be?

Is the plastic having an adverse effect?

My XRF is in 'general metals' mode; does it need calibrating to detect the $\ce{Ca}$?

$\endgroup$
  • 1
    $\begingroup$ This is assumption, so not making an official answer for it, BUT: Phosphorous and Ca share peaks so if the amount of Ca and P is within the same order of magnitude it could be you need a calibration or better equipment to handle that mixture. I know because at my place of work we are managing the same issue, only we are interested in the P content. There is a special set of calibrations and control samples to reduce the problem. $\endgroup$ – Stian Yttervik May 9 '17 at 16:43
2
$\begingroup$

Ca cannot be detected in General Metal Mode. You have to change to "Mining Mode" In this mode, you can measure Ca properly.

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.