Packaging and storage
Preserve in well-closed containers.
Saponification cloud test
Place 3.00 g in a round-bottom, 100-mL boiling flask fitted with a ground-glass joint. Add 30 mL of a solution prepared by dissolving 40 g of potassium hydroxide in about 900 mL of aldehyde-free alcohol maintained at a temperature not exceeding 15
, and then when solution is complete, warming to room temperature and adding aldehyde-free alcohol to make 1000 mL. Reflux the mixture gently for 2 hours. At the end of this period, open the flask, insert a thermometer into the solution, and place the flask in a container of water at a temperature of 80
. Rotate the flask in the bath while both the bath and the solution cool: the solution shows no cloudiness or globule formation before the temperature reaches 65
Fats or fatty acids, Japan wax, rosin, and soap
Boil 1 g for 30 minutes with 35 mL of 3.5 N sodium hydroxide contained in a 100-mL beaker, maintaining the volume by the occasional addition of water, and allow the mixture to cool at room temperature for about 2 hours: the wax separates, leaving the liquid clear, turbid, or translucent, but not opaque. Filter the cool mixture, and acidify the clear filtrate with hydrochloric acid: the liquid remains clear or shows not more than a slight amount of turbidity or precipitate.
Acid value 401
Warm about 3 g, accurately weighed, in a 200-mL flask with 25 mL of neutralized dehydrated alcohol until melted, shake the mixture, add 1 mL of phenolphthalein TS, and titrate the warm liquid with 0.5 N alcoholic potassium hydroxide VS to produce a permanent, faint pink color: the acid value so obtained is between 17 and 24.
Ester value 401
To the solution resulting from the determination of Acid value
add 25.0 mL of 0.5 N alcoholic potassium hydroxide VS and 50 mL of aldehyde-free alcohol, reflux the mixture for 4 hours, and titrate the excess alkali with 0.5 N hydrochloric acid VS. Perform a blank determination (see Residual Titrations
under Titrimetry 541
). The ester value so obtained is between 72 and 79.