Published Online: 1 January 1975
Page Count: 6
Research criminalist, Illinois Bureau of Identification, Joliet, Ill.
Associate chemist, Argonne National Laboratory, Argonne, Ill.
(Received 25 March 1974; accepted 12 July 1974)
The neutron activation technique for firearm residue detection  is well known but not extensively applied. Additional work utilizing an optimized firearm residue detection technique by neutron activation analysis (NAA)  it made it clear that postirradiation radiochemical separations are the cause of several limitations which discourage a more general use of neutron activation analysis. The inherent time limitation due to 87-min half-life of 139Ba necessitates fast manipulations of radioactive solutions, which in turn requires an experienced radiochemist. In addition, there is an ever-present danger of overexposure and contamination. Besides, typically only a dozen samples can be irradiated per batch, which makes the method quite expensive. The developed statistical treatment bivariate-normal analysis  is inconvenient for routine applications. With this in mind, a method was developed which: (1) eliminates postirradiation radiochemistry and thus maximizes time for analysis, (2) accommodates over 100 samples per irradiation capsule (rabbit); (3) does not require a collection of occupational hand blanks, and (4) utilizes a simplified statistical concept based on natural antimony (Sb) and barium (Ba) levels on hands for the interpretation of data .
Paper ID: JFS10247J