... .999%. The total content of Ag, Al, As, Au, Cd, Cr, Cu, Fe, Mg, Ni, Pb, Sn & Zn is bellow 10 ppm;2 ... above 99.9999%. The total content of Ag, Al, As, Au, Cd, Cu, Fe, Mg, Ni, Pb & Zn is bellow 1ppm;3. Grade ... 99.9999%. The total content of Ag, Al, As, Au, Cd, Cu, Fe, Mg, Ni, Pb & Zn is bellow 0.1ppm;3, Physical ...