Modified fluorometric determination of vitamin A in milk.

A modified fluorometric procedure for determination of vitamin A in milk was developed to provide rapid analysis of large numbers to samples.. Saponification and a single extraction in a reaction vessel without transfer provided simplicity and standardization. Time and temperature of saponification and time of extraction were studied. Fifteen replicates of four different milks gave standard deviations of .71, .82, 1.26, and .71 on samples with 29, 26, 38, and 26 mug retinol per 100 ml. Recovery of added vitamin A in six amounts in two experiments gave ranges of recovery of 96.0 to104.0 and 95.2 to 105.3% with average recoveries of 100.0 and 99.9%.