Calcium issue

Hi everyone, I am trying to quantitate calcium and silicon by ICP-OES in a polymer film.  The sources are calcium chloride and silicon dioxide in the film.  I am using microwave digestion with nitric acid and HF for preparation, which results in a clear solution.  My problem is that i am getting only about 50% recovery for calcium.  Any suggestions?

  • Hello Tyler,

    Can you tell us some more?
    What are the concentrations you are working with?
    What settings are you using?
    It is highly likely that the recovery is low because of the sample preparation. Have you checked with an internal standard addition? You can add the IS before sample prep (digestion) and also after sampler prep. You should try both and see how your recovery looks.
    You should also try a digestion of a neat calcium sample once and then optimize the conditions until you get good recovery rates.

    Hope this helps.

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