Quality standard（GB/T915-1995）: TEST SPECIFICATION（99.99%） SPECIFICATION（99.997%） Cu 10.0ppm 3.0ppm Pb 10.0ppm 7.0ppm Zn 5.0ppm 1.0ppm Fe 10.0ppm 5.0ppm Ag 40.0ppm 5.0ppm As 3.0ppm 0.5ppm Te 5.0ppm 棗? Sb 5.0ppm 3.0ppm Sn 棗? 2.0ppm Cl 15.0ppm 棗? Cd 棗? 1.0ppm Hg 棗? 0.5ppm Ni 棗? 5.0ppm Content ≥99.997% ≥99.997%