Items

Standard

Result

Appearance

White crystal

White crystal

Assay    

99.50%-101.0%

99.97%

Melting point

168°C-171°C

169.4°C-170.6°C

Insolubles

0.03% max

0.005%

ASH

0.05% max

0.005%

Heavy metals

5ppm max

2ppm

Loss on drying

0.2% max

0.1%

PH

10.0-10.8

10.4

Color

5#

5#

Fe

1ppm max

0.5ppm

SO42+

10ppm max

3pm

Cl

3ppm max

1ppm

Abs (260nm,20%water)

0.1 max

0.05