By Anonymous on Wednesday, April 7, 2004 - 04:54 am:

Hi

I am trying to analize titanium dioxide in sunscreens, do you know any method references?

Thanks

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By Durk on Wednesday, April 7, 2004 - 07:27 am:

We tried it with ICP-MS, but the results were not satisfying. The reproducibility was very bad probably due to the diameter of the particles of Ti in the samples.

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By Consumer Products Guy on Wednesday, April 7, 2004 - 08:25 am:

What about as insolubles? Much easier than getting TiO2 to dissolve in hot sulfuric acid for spectrophotometric assay.

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By bill tindall on Wednesday, April 7, 2004 - 03:26 pm:

If there is nothing else nonvolatile in there I would do it gravimetrically after an ashing.

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By Anonymous on Wednesday, April 28, 2004 - 11:43 am:

Hi,

Does anyone have a spectrophotometric method I could see for TiO2? I have heard of this as a method for TiO2 in sunscreens, but I'm having the hardest time finding any literature.

Also, if anyone knows of a method for ZnO in sunscreens, that would also be greatly appreciated!!

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By Anonymous on Friday, July 2, 2004 - 04:05 am:

Have you considered analysis by microwave digestion with HF and HNO3 and analysis by AA or ICP?

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By juddc on Friday, July 2, 2004 - 09:05 am:

Amen to last anon...

In a prior life, I had to develop such an assay and I did just that. Worked well, but there were occasional matrix issues that needed working through depending on the sample.

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By Anonymous on Tuesday, July 6, 2004 - 10:58 am:

I do not have an AA or ICP. I'm looking to do a method by using a muffle furnace (ashing). For anyone who has done this, is there any specific advice you can give with this approach? Thanks