... .0%≥99.0%( anhydrous basis)Acidity and AlkalinityAccord with the test--Sulphate,≤%0.015--Heavy metals(As Pb), ≤%0.0010.0005Oxalate ... (As H2C2O4), ≤%0.030.01Easy carbonify substanceAccord with the test--Chloride, ≤%0.005--Loss on drying,11.0-13.0 ... -9Arsenic(As),≤ppm--1Lead(Pb),≤ppm--1Mercury(Hg),≤ppm--1 sodium citrate