Ingredient Item Cn As Co Pb Zn TFe F SiO2 In acid solution 0 0.003 0 0 0.08 0.94 0 0.4 In alkaline solution 0 0.004 0 0 0.04 0 0 1.1 In neuter solution 0 0.005 0 0 0.09 0 0 0.4 Standard requirements 0.05 0.04 1.0 0.1 1.0 0.3 1.0