[Standard]: GB535-1995

[Molecular formula]: (NH₄)₂SO₄

[Molecular weight]: 132.141

[Properties]:

Item	Value			Test method
	Premium grade	First grade	Salable product
appearance	white crystal , no mechanical impurities	no mechanical impurities		eyeballing
N assay (dry)	21.0	21.0	20.5	ISO3322-75
moisture(H2O)	0.2	0.3	1.0	weight
free acid (H2SO4) assay	0.03	0.05	0.20	ISO2993-74
Fe	0.007	-	-	spectrophotometry
As	0.00005	-	-	GB 4097.6-83
heavy metal(as Pb) assay	0.005	-	-	turbidimetric method
water insoluble matter	0.01	-	-	ISO2994-74

[Properties]: White odorless rhombus crystal with sale taste.

[Uses]: Fertilizer, dyeing assistant, food catalyst, buffer, bating material.

[Packing & storage]: 50kg in woven bag lined with polythene bag, avoid heat and moisture, no mixed with basic matter