Certified Reference Material (CRM).

100 mg/L each of Al, As, Pb, Sb, Se, Tl, 50 mg/L each of Ba, Co, Cu, Ni, 20 mg/L each of Cr, Fe, Mn, 10 mg/L Ag, 5 mg/L each of Be, Cd in HNO₃ 5%, tr. HF