|
L-Cysteine
Hydrochloride Monohydrate
|
 |
|
C3H7NO2S·HCl·H2O
175.6 |
7048-04-6 |
| DEFINITION |
|
Cysteine hydrochloride
contains not less than 98.5 per cent and not more than the
equivalent of 101.0 per cent of (R)-2-amino-3-mercaptopropanoic
acid, calculated with reference to the dried substance.
|
|
CHARACTERS
|
|
A white, colourless powder
or colourless crystals, freely soluble in water, slightly
soluble in alcohol, practically insoluble in ether.
|
| IDENTIFICATION |
| Infrared absorption
spectrophotometry |
| TESTS |
| Appearance
of solution |
Clear and
meets the requirements |
|
Specific
optical rotation |
+5.5º to +7.0º |
| Ninhydrin-positive
substances |
Meets the requirements |
| Sulphates |
Limit: 300 ppm |
| Ammonium |
Limit:200 ppm |
| Iron |
Limit:20 ppm |
| Heavy
metals |
Limit:10 ppm |
| Loss
on drying |
8.0 per cent to 12.0
per cent |
| Sulphated
ash |
Not more than 0.1 per
cent |
|
ASSAY |
98.5 per cent to 101.0 per
cent |
| STORAGE |
| Store in a well-closed
container, protected from light. |
