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Gradient Reversed Phase HPLC Procedure for Smokeless Powder Comparison

NCJ Number
193736
Journal
Journal of Forensic Sciences Volume: 47 Issue: 1 Dated: January 2002 Pages: 168-174
Author(s)
Chad E. Wissinger B.S.; Bruce R. McCord Ph.D.
Date Published
2002
Length
7 pages
Annotation
This report details a procedure for the detection of components in smokeless powders by gradient HPLC.
Abstract
Extracting additives and stabilizer degradation products from the powder using methylene chloride and analyzing the results by gas chromatography/mass spectrometry is commonly carried out in smokeless powder comparisons. Some of these components are thermally unstable, making comparison of similar powders of or powders originating from different manufacturing lots difficult when GC is used. Isocratic HPLC analysis using C-18 stationary columns can be unsatisfactory due to a wide range of polarities of the additives and stabilizer degradation products and the presence of geometrical isomers. In this paper, the investigators analyze a gradient procedure using a C-8 column of smokeless powders. This procedure provides a separation of a wide range of components present in smokeless powders. This paper provides analytical figures of merit and UV spectra of each of the components. In addition, the procedure is evaluated by comparing four different lots of smokeless powder from the same manufacturer. The results show that this method can be used to separate geometric isomers of nitrotoluenes and nitrodiphenyl amines present in additives and stabilizer degradation products of these powders. The technique can also be used to determine lot-to-lot variations among different samples of smokeless powders. The combination of retention time and UV spectra of each component can be used to quickly determine the composition of the powder, and the ability to distinguish between lot samples make this technique a powerful tool for the forensic laboratory. Figures, references