Certified Reference Material (CRM).

200 mg/L each of Al, As, Ba, Se, Tl, 100 mg/L Fe, 50 mg/L each of Co, Mn, Ni, Pb, Sb, V, Zn, 25 mg/L Cu, 20 mg/L Cr, 5 mg/L each of Ag, Be, Cd in HNO₃ 5%