zinc sulphate Quality standard( HG/T2326-92,HG/2934-2000)ItemZnSO4•7H2OTop-gradeFirst gradeQualified productPurity≥99.097.092.0Zn%≥22.5122.0620.92PH(50g/L)≤3.03.0........Cl%≤0.200.60........Pb%≤0.0020.0100.010Fe%≤0.00500.0200.060Mn%≤0.010.10........Cd%≤0.0020.010........Cu%≤0.002.................Insoluble matter %≤0.0200.0500.10