白色结晶或结晶性粉末 
 

    
        
            
            
Item
            
            
            
Standard
            
        
        
            
            
Appearance
            
            
            
White crystals or crystalline powder
            
        
        
            
            
Specific rotation[α]20/D(C=4,H2O)
            
            
            
+25.8 to 27.0°
            
        
        
            
            
State of solution
            
(Transmittance)
            
            
            
Clear and colorless
            
        
        
            
            
Chloride (Cl)
            
            
            
Not more than 0.020%
            
        
        
            
            
Ammonium (NH4)
            
            
            
Not more than 0.02%
            
        
        
            
            
Sulfate (SO4)
            
            
            
Not more than 0.020%
            
        
        
            
            
Iron (Fe)
            
            
            
Not more than 10ppm
            
        
        
            
            
Heavy metal(Pb)
            
            
            
Not more than 10ppm
            
        
        
            
            
Arsenic(As2O3)
            
            
            
Not more than 1ppm
            
        
        
            
            
Loss on drying
            
            
            
Not more than 0.20%
            
        
        
            
            
Residue on ignition(sulfated)
            
            
            
Not more than 0.10%
            
        
        
            
            
Assay
            
            
            
98.5 to101.0%
            
        
        
            
            
pH
            
            
            
2.6 to 3.6
            
        
        
            
            
Ninhydrin positive substance
            
            
            
negative