Certified Reference Material (CRM).

500 mg/L Fe, 250 mg/L each of Ba, Zn, 100 mg/L each of Co, Cr, Cu, Mn, Ni, Sb, V, 50 mg/L each of As, Pb, 25 mg/L each of Ag, Be, Cd, Se, Tl in HNO₃ 5%