L-Threonine
|
|
C4H9NO3
119.1 |
72-19-5 |
DEFINITION |
Threonine contains not less
than 99.0 per cent and not more than the equivalent of 101.0
per cent of (2S,
3R)-2-Amino-3-hydroxybutyric acid, calculated with reference to the dried substance.
|
CHARACTERS
|
A white, crystalline powder
or colourless crystals, soluble in water, practically
insoluble in alcohol and in ether.
|
IDENTIFICATION |
Infrared absorption
spectrophotometry |
TESTS |
Appearance
of solution |
Clear and
meets the requirements |
pH |
5.0 to 6.5 |
Specific
optical rotation |
27.6º to -29.0º |
Ninhydrin-positive
substances |
Meets the requirements |
Chlorides |
Limit: 200 ppm |
Sulphates |
Limit: 300 ppm |
Ammonium |
Limit:200 ppm |
Iron |
Limit:10 ppm |
Heavy
metals |
Limit:10 ppm |
Loss
on drying |
Not more than 0.5 per
cent |
Sulphated
ash |
Not more than 0.1 per
cent |
ASSAY |
99.0 per cent to 101.0 per
cent |
STORAGE |
Store in a well-closed
container, protected from light. |