AOAC Official Method 936.10 Benzaldehyde in Almond Extract Gravimetric Method
First Action 1936
Final Action 1992
Measure 10 mL test sample into each of two 300 mL Erlenmeyers and add 10 mL phenylhydrazine solution (3 mL CH3COOH, 40 mL H2O, 2 mL phenylhydrazine) to one flask and 15 mL to other. Let mixtures stand overnight in dark place. Add 200 mL H2O and filter through weighed Gooch provided with thin layer of glass fiber filter. Wash precipitate first with cold H2Oand finally with 10mL10% alcohol. Dry3hat 70°C at pressure
£100 mm Hg (13.3 kPa) or to constant weight over H2SO4. Weight precipitate ´5.408 = weight benzaldehyde in 100 mL sample. If the 2 determinations do not agree, repeat operation, using larger volume phenylhydrazine solution.
References: JAOAC 19, 408(1936); 24, 665(1941).
CAS-100-52-7 (benzaldehyde)
Revised: March 1996
