Colouring matters, oil-soluble, synthetic. Isolation and identification. (NMKL 32, 1959)
The colouring matters are extracted with acid mixtures, and transferred to ethyl ether after dilution with water, respectively dilution and alkalization. The ether extract is washed with water, and the ether evaporated. The
residue is saponified with potassium hydroxide in alcololic solution. The unsaponifiable fraction is isolated, and dissolved in acetic acid ethyl ester. The colouring matters are separated by paper chromatograph and identified by
comparison with standard colours.
Colouring matters (NMKL 32)