Span 80 - sorbitan oleate analysis

[dkollmorgen]

Hello Everyone:

Does anyone have any methods/suggestions as to how I can analyze for sorbitan oleate? We have been trying to use both GC and HPLC, but are not having much luck. Any assistance would be most appreciated. We have never worked with this type of compound before.

thanks,
Diane

[AdrianF]

I have referred to the BP and discovered that sorbitan oleate is a mixture of compounds

DEFINITION (BP)
Mixture usually obtained by esterification of 1 mole of sorbitol and its mono-and di-anhydrides per mole of oleic acid.

If deesterified amixture of acids are obtained which can be analysed by GC

Method from BP 2007
Carry out the saponification for 1 h.

Composition of fatty acids
Gas chromatography (2.4.22, Method C).

Composition of the fatty acid fraction of the substance:
— myristic acid : maximum 5.0 per cent,
— palmitic acid : maximum 16.0 per cent,
— palmitoleic acid : maximum 8.0 per cent,
— stearic acid : maximum 6.0 per cent,
— oleic acid : 65.0 per cent to 88.0 per cent,
— linoleic acid : maximum 18.0 per cent,
— linolenic acid : maximum 4.0 per cent,
—fatty acids with chain length greater than C 18 : maximum 4.0 per cent.

Hope this helps