Item Tolerance Test Result
Appearance White or yellowish-white powder Complies
Identification The substance dissolves Complies
pH (1.0g in 20.0ml) 3.0~7.0 4.1
Water ≤ 5.0% 3.0%
Vinylpyrrolidinone ≤ 0.2% 0.01%
K-value 25.0-34.0 29.5