AOAC Official Method 932.09 Glycerol in Eggs
Qualitative Test
Procedure
A. Reagent
Fuchsin-bisulfite solution.—Dissolve 0.2 g basic fuchsin in 120 mLhotH2Oand cool; add solution of 2 g anhydrous Na2SO3 in 20mL H2O, and then 2 mL HCl. Dilute solution with H2O to 200 mL and let stand 1 h.
B. Detection
Add 20 mL alcohol to ca 5 g test portion in Erlenmeyer flask. Shake vigorously, and filter through 12.5 cm fluted paper. Evaporate filtrate rapidly until no odor of alcohol is perceptible, cool, and add 3–4 drops H2O. Add 10–15 mL anhydrous ether. Carefully mix solutions, let separate, and pour off as much of ether layer as possible, disregarding cloudiness in this layer. Shake well with two 10 mL portions anhydrous ether, pouring off ether carefully in each case. (Volume of aqueous solution should be ³0.4–0.5 mL.) Evaporate remaining liquid on steam bath to 0.1–0.2 mL. Cool, and add 15 mL mixture of equal volumes absolute alcohol andCHCl3. Cool, shake, and let stand 5 min.
