NCJ Number
1904
Date Published
1970
Length
261 pages
Annotation
CHARACTERIZATION OF PAINT SAMPLES IS EXAMINED AS A POTENTIAL APPLICATION OF NEUTRON ACTIVATION ANALYSIS IN SCIENTIFIC CRIME DETECTION.
Abstract
A VARIETY OF PAINTS WERE ANALYZED, UTILIZING THE PURELY INSTRUMENTAL PROCEDURE OF NEUTRON ACTIVATION FOLLOWED BY GAMMA RAY SPECTROMETRY AND COMPUTERIZED DATA REDUCTION, AND THIRTY-SEVEN DIFFERENT ELEMENTS WERE OBSERVED. THE MAXIMUM NUMBER OF ELEMENTS QUANTITATIVELY OBSERVED IN ANY ONE PAINT WAS 25, AND THE AVERAGE NUMBER OBSERVED IN ANY ONE SAMPLE WITH MODERN GAMMA RAY SPECTROMETRY TECHNIQUES WAS 15. THE WORK CULMINATED IN THE EXAMINATION OF 155 DIFFERENT PAINTS (SOME SAMPLED IN REPLICATE) TAKEN FROM THE ENVIRONMENT ACCORDING TO A STRATIFIED RANDOM SAMPLING MODEL DERIVED FROM AN ENVIRONMENTAL SURVEY. IT WAS POSSIBLE TO PREDICT, WITHIN THE LIMITS OF DISTRIBUTION DATA PROVIDED BY THE DATA SET OF 155 PAINTS THE PROBABILITIES OF OTHER COMBINATIONS OF CONCENTRATIONS AND THE PROBABILITIES OF ACCIDENTAL MATCHING OF TWO DIFFERENT PAINT SAMPLES. AS A RESULT OF THIS WORK THE NAA METHOD WAS SHOWN TO BE AN EFFECTIVE MEANS OF COMPARING PAINT SPECIMENS FOR FORENSIC PURPOSES.