Vitamin A in Mixed Feeds

The Stability of Vitamin A in Mixed Feeds and Premixes

“…Vitamin A was determined by the method of the Association of Official Agricultural Chemists (Cooley, 1951).…”

Food

“…Spot tests with antimony trichloride serve as the indicator for the collection of appropriate fractions which are then measured spectrophotometricallv. Improvement of the adsorption step in the assay of mixed feeds for vitamin A has been effected by substituting a mixture of activated magnesia and diatomaceous earth (Hyflo Super-Cel) for sodium carbonate previously suggested by the same group of workers (27). In the determination of vitamin A esters no interference is encountered from lycopene and carotene, but the latter is not readily separable from vitamin A alcohol by this procedure.…”