|
Appearance
|
White crystalline powder
|
|
Assay (iodometric)
|
95 - 99.9%
|
|
Iodometric,SO2
|
54.8 - 57.6%
|
|
Appearance of solution
|
Passes test
|
|
pH (5% solution in water)
|
3 - 4.5
|
|
Chloride (Cl)
|
Max 0.05%
|
|
Heavy metal (as Pb)
|
Max 0.001%
|
|
Thiosulphate
|
Passes test
|
|
Copper (Cu)
|
Max 0.0025%
|
|
Zinc (Zn)
|
Max 0.0025%
|
|
Iron (Fe)
|
Max 0.002%
|
|
Selenium (Se)
|
Max 0.0005%
|
|
Arsenic (As)
|
Max 0.0002%
|
|
Mercury (Hg)
|
Max 0.0001%
|