White crystals or crystalline powder

    
        
            
            
Item
            
            
            
Standard
            
        
        
            
            
Appearance
            
            
            
White crystals or crystalline powder
            
        
        
            
            
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