DIN 38406-21:1980
德国检验水、废水和污泥的标准方法.阳离子(E组).九种重金属(Ag 、Bi、Cd、Co、Cu、Ni、Pb、Ti 及Zn )的测定(E21)
German standard methods for the examination of water, waste water and sludge; cations (group E), determination of nine heavy metals (Ag, Bi, Cd, Co, Cu, Ni, Pb, Tl, Zn) (E21)