... o C, easily soluble in water, with remarkable chelating ability to some metal ions such as Ca 2+, Mg 2+, can soften ... of petroleum product, gum latex storage, as dispersant, solvent in metal industry and pharmaceutical industry, also widely used in gum synthesis ... pH of 1% water solution 9.5-10.0 Heavy metal, as Pb %; 0.001 Arsenic, as As, %; 0.0003 Fluoride ...