Item

Standard

Appearance

White crystals or crystalline powder

Specific rotation[α]20/D(C=2,H2O)

-14.0°to-17.0

Transmittance

Not less than 95.0%

Heavy metal(Pb)

Not more than 20ppm

Arsenic(As2O3)

Not more than 2ppm

Other amino acids

Chromatographically

not  detectable

Loss on drying

Not more than 0.50%

Residue on ignition

Not more than 0.30%

Assay

98.0to102.0%

pH

1.7to2.8