文档介绍：MAGNESIUM OXIDE
Prepared at the 17th JECFA (1973), published in FNP 4 (1978) and in FNP
the acid should be consumed. Evaporate 25 ml of the filtrate to dryness and
dry at 105o for 1 h. Not more than 10 mg of residue should remain.
Calcium oxide Not more than %
Weigh 400 mg of the sample to the nearest mg, and dissolve in a
mixture of 3 ml of sulfuric acid and 22 ml of water. Add 50 ml of ethanol,
and allow the mixture to stand overnight. If crystals of magnesium sulfate
separate, warm the mixture to about 50o to dissolve. Filter through a tared,
previously ignited, porcelain filter crucible, and wash the precipitate severaltimes with a mixture of 2 volumes of ethanol and 1 volume of dilute sulfuric
acid TS. Ignite the crucible and contents at a dull red heat, cool and weigh.
The weight of calcium sulfate obtained, multiplied by , gives the
equivalent of calcium oxide in the sample taken for the test.
Lead (Vol. 4) Not more than 2 mg/kg
Determine using an atomic absorption technique appropriate to the