Estimation of vitamin A in industrially produced feeds. 2. Estimation of vitamin A in mixed feeds
Muller, V.; Lengerken, J. v; Kirmas, D.; Wetterau, H.
Nahrung 20(1): 47-55
For part 1 see NAR 45, 4971.2. The sample was saponified, chromatographed to remove carotenoids and vitamin A was estimated by the Carr-Prince reaction. In another method not requiring chromatography an extract with dichloromethane was dehydrated with p-toluenesulphonic acid and treated with diethylamine and extinction at 397 nm was measured.