TiO2

[Catharina]

Hallo everybody I know it is not chromatographic question but I would like ask: do you have some experience on TiO2 determination in pharmaceutical product? I am looking for fast and simple identification method. I wll be very grateful for suggestions

[Mark Tracy]

I looked in USP. TiO2 is assayed by a complicated reduction and titration method. They didn't have anything for identification. For a quick ID check, I would look into microscopy with polarized light.

[Bruce Hamilton]

Find somebody with a spectrometer ( Emission, AAS, ICP etc.,).

The following should work, but I always found the bigest problems with TiO2 in samples was getting it into solution. Always do a control by spiking some of your sample. The first colour method is from the ID tests in both USP and EP, the second only in the EP. More details in each..

Digest a small sample in hot conc sulphuric acid to clear solution, dilute with water. To an aliquot of the sample solution, add hydrogen peroxide solution, a yellow-to red colour will form. To a second aliquot, add zinc granules, and more H2SO4, if necessary. After 45 minutes, expect a violet-blue colour.

Good luck,

Bruce Hamilton

[Catharina]

Thank you for answer. Yes, AAS, ICP it is good idea but I it is my second idea. First I should try methods from EP or USP.

[Mark Tracy]

Quite honestly, if I had access to an ICP, that would be my first choice. The USP titrimetric method has to be done in oxygen-free special glassware. The sample dissolution process is ugly either way. If this is some one-off job or short-term project, I would hire it out.

[Chris]

I have had limited experience of a TiO2 method that involved ashing the sample off then using a colourmetric based UV method. Bit vague but i think it may have been based on the EP (possibly on one of the id methods). 30 samples a day was no problem.

[Chris]

I have had limited experience of a TiO2 method that involved ashing the sample off then using a colourmetric based UV method. Bit vague but i think it may have been based on the EP (possibly on one of the id methods). 30 samples a day was no problem.