4 modified Emmerie and Engel test has been evolved to avoid norilinearity, high or variable blanks and the use of corrosive solvents. A solution of the saponified material in light petroleum is purified by chromatography, the tocopherol being adsorbed on mildly alkaline alumina, washed I\ itli diethyl etherlight petroleum solvent and subsequently eluted with chloroform. The eluate is concentrated by evaporation and treatccl with chlorolorm solutions of ferric chloride and 2 :2'-dipyridyl. -4fter the sohtion h , s stood for 5 minutes, a measured volume of water is added and the optical density of the aqueous extract is determined a t 520 m p ; altcrnati\dy the depth of colour, which is stable for some hours, may be assessed visually, e.g., by comparison with a standard cobalt sulphate solution. The only interference encountered has been from highly oxidised caroteiioids, for which correction is possible.Sensitivity is five times that of the original Emmerie and Enqel test and precision is about 5 per cent.
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