Retention of radioactive tracers in dry ashing of blood

An alternate method of decomposing organic material utilizes a stream of oxygen excited by an electrical discharge. The effects of the oxygen method on the loss of tracers from blood were studied and compared with those of conventional dry ashing. The results for the oxygen method show that Sb, As, Cr, Co, Fe, Cu, Pb, Mn, Mo, and Zn are quantitatively retained in the combustion boat, but that Xu, Hg, and Ag were partially volatilized. However, the three volatilized elements were redeposited within the glass system and could be recovered by rinsing the inside with mineral acids. Preliminary experiments indicate that the oxygen method is applicable to other biological materials. (D.L.C.)