Object of determination

National Standard

Self-control Standard

Test result

appearance

free-flowing white powder

free-flowing white powder

sodium sulphate (Na2SO4),

≥99.0

≥99.05

99.1

insoluble matter in water,

≤0.05

≤0.04

0.03

calcium & magnesium(Mg+),

≤0.15

≤0.15

0.03

chloride (Cl),

≤0.35

≤0.24

0.22

iron(Fe),

≤0.002

≤0.001

0.0006

moisture,

≤0.20

≤0.04

0.03

whiteness,

≥80

≥83

89

PH(Na2CO3),

8- 9