Items	Specifications	Results
Characteristic	White or slight yellow crystalline powder	Slight yellow crystalline powder
Identification	Should be positive reaction	Positive reaction
Clarity of solution	Should be comply	Comply
PH	3.0~4.5	3.4
Related substance	Should be comply	Comply
Fluoride	≥4.7%	Comply
Water	≤6.7%	6.3%
Residue on ignition	≤0.1%	0.03%
Heavy metal	≤20PPM	＜20PPM