Quantify Silicon in Silicone Oil by ICP-OES Follow-up Question

Advice By Paul Gaines, Ph.D
I've tried digestion in microwave assisted method to quantify silicon in silicone oil, but as I told you before, I did not succeed. According to oil supplier, silicone oil contains around 38% in Si; All results are always below this number.

In my approach I am using closed vessel digestion and the mixture HNO3 (4 mL) + H2O2 (2mL) +HF (1mL). Also, I have tried to match samples and standards as much as I can.

Now, I would like to try direct analysis after pretreating the sample with alcoholic KOH. This approach was mentioned by you in your last e-mail and is briefly described in your periodic table Silicon element

Please:
  • What kind of vessel may I perform the sample pretreating once KOH could attack platinum crucible?
  • What is KOH concentration in alcohol?
  • This destructions is performed at room temperature?
  • What about standards? Should I use them in KOH/Xylene?

 

Hi again - please see the following and then call if any additional info is needed:

 

  • What kind of vessel may I perform the sample pretreating once KOH could attack platinum crucible?
    I would use a LDPE bottle from Nalgene (HDPE has some Si) and mix the sample with the alcoholic KOH and place in a water bath or oven at 60 deg C.
  • What is KOH concentration in alcohol? 0.5 M
  • This destructions is performed at room temperature? 60 deg C
  • What about standards? Should I use them in KOH/Xylene? Yes.


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Serving you in chemistry,
Paul R. Gaines, Ph.D.
CEO of Inorganic Ventures

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