Item

Specification

Photo grade

Medicine grade

Appearance

White Crystal

White Crystal

Assay% ≥

99.5

99.0

Loss on Drying% ≤

0.2

0.5

Transmit of 20% Solution 410 nm% ≥

96

PH of 5% aqueous solution

4.5-5.5

4.5-5.5

Chlorides(as Cl)% ≤

0.1

0.5

Iodides(as I)% ≤

0.006

Pass test

Sulfates(as SO4)% ≤

0.005

0.01

Resistance to KMnO4 Minutes ≥

10

Heavy Metals(as Pb)PPM ≤

3

5

Iron(as Fe2O3)PPM ≤

2

Non-Volatiles% ≤

0.01

Alkal Earth Meatls(as Ca)% ≤

0.005

Pass test

Water Insolubles% ≤

0.005

Arsenic(as As)PPM ≤

3