Identification
The specific rotation of the uninverted solution obtained in the
Assay is not less than 62.6
, and the acid-inverted solution obtained in the
Assay is levorotatory.
Chloride, Sulfate, Calcium, and Heavy metals
Transfer about 20 g, accurately weighed, to a 100-mL volumetric flask, add 80 mL of water, shake to dissolve the sucrose, then add water to volume, and mix. Separate the solubilized sucrose from any insoluble matter by filtration until the filtrate is sparkling clear, and use the freshly prepared, clear filtrate for the following tests.
Chloride 221
A 10-mL portion shows no more chloride than corresponds to 0.40 mL of 0.020 N hydrochloric acid (0.014%).
Sulfate 221
A 25-mL portion shows no more sulfate than corresponds to 0.50 mL of 0.020 N sulfuric acid (0.010%).
Heavy metals 231
To a 20-mL portion add 4 mL of water and 1 mL of 0.1 N hydrochloric acid: the limit is 5 ppm.
Assay
Transfer 26.0 g of Compressible Sugar, previously dried and accurately weighed, to a 100-mL volumetric flask, add about 0.3 mL of a saturated aqueous solution of lead acetate, shake with about 90 mL of water, dilute with water to volume, and mix. Distribute evenly on the surface of a sheet of medium-fast filter paper about 8 g of chromatographic siliceous earth suitable for column partition chromatography (see under
Reagents in the section
Reagents, Indicators, and Solutions), and filter the solution, with the aid of vacuum, discarding the first 20 mL of the filtrate. Pipet 25 mL of the subsequent clear filtrate into each of two 50-mL volumetric flasks. Slowly add 6 mL of dilute hydrochloric acid (1 in 2) to one flask while rotating it, dilute with water nearly to volume, and mix. Place the flask in a water bath maintained at a temperature of 60
, continuously shake the flask in the bath for about 3 minutes, and allow the flask to remain in the bath for a total of 10 minutes. Immediately cool to 20
by plunging the flask into a cold bath, dilute with water to volume at 20
, and mix. Cool the contents of the second flask to 20
, dilute with water to volume at 20
, and mix. Maintain both flasks at a temperature of 20
for 30 minutes. Determine the specific rotation of each solution at 20
as directed under
Optical Rotation 781. Calculate the percentage of C
12H
22O
11 taken by the formula:
in which
o and
i are the specific rotations of the uninverted and acid-inverted solutions, respectively.