Neutron Activation Analysis Using 1-Pyrrolidinecarbodithioate Extraction

Abstract

For the radioactivation analysis of environmental specimens, such as biological and airborne particulate samples, a new group separation method using 1-pyrrolidinecarbodithioate extraction has been developed. A sample irradiated in an atomic reactor for 1 or 5 hours is dissolved with hot HNO^3-ELSO, mixture, and the resultant solution is adjusted to pH 3. O. Transition elements, expept manganese, are extracted into chloroform solution of pyrrolidinecarbodithioate, and manganese is then extracted from the aqueous solution of pH 7. O. The analyzed elements are separated into the following four groups; halogens are separated into the distillate of wet ashing procedure, biologically essential or toxic transition elements into the pH 3 extraction phase, manganese into the pH 7 extraction phase, and alkali, alkaline earth and rare earth elements into the residual aqueous phase. The elements in each phase are determined by gamma-ray spectrometry using a Ge (Li) detector.
Among the elements observed, no quantitative groupings could be performed on chromium, antimony and arsenic by the present procedure.
The best scheme of the group separation was based on the fundamental study on the behavior of the elements using radioactive tracers.
The validity of the method was demonstrated by analyzing NBS standard reference materials Orchard Leaves and Bovine Liver, as well as the airborne particulates collected in Kobe City, and by comparing the data obtained with those certified by NBS or with current literature data.