Comparative study of methods for determining lanthanide elements in biological materials by using NAA, HPLC postcolumn reaction, and ICP-MS.

Mice were injected intravenously with one of the following elements: Y, La, Ce, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, or Yb, at a dose of 25 mg/kg body wt. After 20 h, the various organs were taken out, and the element concentrations were determined by NAA, HPLC postcolumn reaction, or ICP-MS. The results by these three methods were within the acceptable range. About 85% of the amount administered of each element was found in liver, lung, and spleen.