We are offering aluminium potassium sulphate extra pure aik(so4)2.12h2o m.w. 474.38 50 kg assay(ex al) 99-102% maximum limits of impurities: chloride(cl) 0.01% ammonium(nh4) 0.05% iron(fe) 0.01% lead(pb) 0.01% cas no. 7784 - 24 - 9 un no. Nr tariff : 2833 30 30 s : 22 - 24 25 f :