Volume 34, Issue 1 (January 1989)
Comparison of Smokeless Powders by Pyrolysis Capillary Gas Chromatography and Pattern Recognition
Four smokeless powder propellants from each of three domestic manufacturers were analyzed by pyrolysis capillary gas chromatography. Pyrograms were compared to see if this was a viable technique for the identification of a questioned smokeless powder. Comparisons were made between particles from the same manufacturer's product and lot, between different lots of the same manufacturer's product, and between different manufacturers' products. The differences between the pyrograms were less than anticipated, and some of the manufacturer's products could not be differentiated from others. Correlation values were computed to quantify the degree to which each pyrogram matched each of the others. The correlation values for within-product comparisons averaged 97.1 out of a possible 100, whereas those for between-product comparisons averaged 80.0. The range of correlation values for between-product comparisons overlapped the range of correlation values for within-product comparisons. This limited the conclusion that could be drawn regarding the origin of a smokeless powder in question.