Packaging and storage
Preserve in well-closed containers.
Loss on drying
731
Dry it at 105

to constant weight: it loses not more than 4.0% of its weight.
Loss on ignition
733
When ignited at 1000

for 1 hour, it loses between 4.0% and 12.0% of its weight.
Volatile matter
When ignited at 600

for 1 hour, it loses between 3.0% and 7.5% of its weight on the dried basis.
Acid-soluble matter
Boil 2.0 g with 100 mL of 0.2 N hydrochloric acid for 5 minutes, and cool. Add water to adjust the volume to 100 mL, and filter. Evaporate 50 mL of the filtrate so obtained to dryness, and ignite the residue at 600

: not more than 0.25 g is found (25%).
Organic volatile impurities, Method IV
467
:
meets the requirements.