Losses of metabolically incorporated selenium in common digestion procedures for biological material.

Two common procedures for wet destruction of biological materials for subsequent determination of selenium have been investigated. Rat organs and biological fluids were endogenously labelled with (75)Se to monitor losses during the procedures. Addition of nitric and perchloric acids with gradual heating up to 210 degrees seemed to be the best method: at this temperature the labelled selenium was still recovered quantitatively, and the destruction was fast and efficient.