Product Name

 S-carboxymethyl-L-cysteine

CAS number

 638-23-3

Molecular formula

 C5H9NO4S

Molecular weight

 179.19

Appearance

 white to slightly off-white amorphous powder

Melting point

205-207ºC

Flash point

191.8ºC

Relative density

1.451g/cm3

Test Item

Specification: European Pharmacopoeia 7TH

Description

A white, crystalline powder, practically insoluble in water, in alcohol and in ether. It dissolves in dilute mineral acids and in dilute solutions of alkali hydroxides.

Identification

Test A (Specific Optical rotation)

It complies with the test for specific optical rotation.

Test B(IR)

The IR spectrum of the sample is concordant with the spectrum of the reference standard, Carbocisteine CRS.

Test C(TLC)

The principal spot in the chromatogram obtained with the test solution (b) is similar in position, color and size to the principal spot in the chromatogram obtained with the reference solution(a)

Test D(Chemical reaction)

. Dark red color is produced, which changes to brown and then to yellow within a few minutes.

pH

2.8 ~3.0

specific rotation [α]D 20

-32.5° ~ -35.5°

State of solution (Transmittance)

Solution S is clear and colourless

Not less than 95.0%

Ninhydrin-positive substances

Not more than 0.5%

Chloride(Cl)

Not more than 0.15%

Sulfate(SO4)

Not more than 0.03%

Heavy metals(Pb)

Not more than 0.001%

Loss on Drying

Not more than 0.5%

Residue on ignition(sulfated)

Not more than 0.3%

Assay

98.5% ~ 101.0 %