... /T 2828-1997 ItemIndexesResultsPotassium bicarbonate, %≥99.099.4Potassium (K), %≥38.038.4Water-insoluble substance, %≤0.010.007Sulfate (K2SO4), %≤0.040.007Heavy metal, % (Pb ... )≤20ppm10ppmArsenic (As), %≤10ppm2ppmFerric oxide (Fe2O3), %≤10ppm7ppmMoisture, %≤0.50.25Chloride (KCL), %≤0.020.008PH value (100g/l solution)8-98.3 ...