Certified Reference Material (CRM).

200 mg/L each of Al, Ba, 50 mg/L each of Co, Mn, Ni, V, Zn, 25 mg/L Cu, 20 mg/L Cr, 10 mg/L Sb, 5 mg/L each of Be, Cd, Ag, Tl, 4 mg/L As, 2 mg/L Pb, 1 mg/L Se in HNO₃ 5%