METHYLp-HYDROXYBENZOATE-对羟基苯甲酸甲酯.pdf

文档介绍：METHYL p-HYDROXYBENZOATE

Prepared at the 51st JECFA (1998), published in FNP 52 Add 6 (199ilter, and wash thoroughly with water. Dry in a
desiccator over sulfuric acid. Determine the melting range of p-
hydroxybenzoic acid so obtained.

PURITYLoss on drying (Vol. 4) Not more than % (over silica gel, 5 h)

Sulfated ash (Vol. 4) Not more than %.
Test 2 g of the sample (Method I)

Acidity Heat 750 mg of the sample with 15 ml of water at 80o for 1 min, cool, and
filter. The filtrate should be acid or neutral to litmus. To 10 ml of the filtrate
add ml of N sodium hydroxide and 2 drops of methyl red TS. The
solution should be yellow without even a light cast of pink.

p-Hydroxybenzoic acid and Dissolve g of the sample, accurately weighed, in 30 ml of ether, add
salicylic acid 20 ml of a 1 in 100 sodium hydrogen carbonate solution, shake, and
separate the water layer. Wash the water layer with two 20 ml portions of
ether, add 5 ml of dilute sulfuric acid and 30 ml of ether, and shake.
Separate