U.S. flag

An official website of the United States government, Department of Justice.

NCJRS Virtual Library

The Virtual Library houses over 235,000 criminal justice resources, including all known OJP works.
Click here to search the NCJRS Virtual Library

FEASIBILITY OF GUNSHOT RESIDUE DETECTION VIA ITS ORGANIC CONSTITUENTS, PART I - ANALYSIS OF SMOKELESS POWDERS BY COMBINED GAS CHROMATOGRAPHY-CHEMICAL IONIZATION MASS SPECTROMETRY

NCJ Number
49639
Journal
Journal of Forensic Sciences Volume: 23 Issue: 3 Dated: (JULY 1978) Pages: 433-445
Author(s)
M H MACH; A PALLOS; P F JONES
Date Published
1978
Length
13 pages
Annotation
THIS PAPER REPORTS GAS CHROMATOGRAPHIC-MASS SPECTROMETRIC ANALYSIS OF VOLATILE ORGANIC COMPOUNDS IN 33 SMOKELESS POWDER SAMPLES TO DETERMINE AN IDENTIFICATION METHOD THAT IS PRECISE, RAPID, AND INEXPENSIVE.
Abstract
SMOKELESS POWDERS COMMONLY USED IN SMALL ARMS AMMUNITION ARE BLENDS OF NITROCELLULOSE AND SMALL AMOUNTS OF STABILIZERS AND PLASTICIZERS, IN ADDITION TO CERTAIN MODIFYING AGENTS. THIRTY-TWO OF THESE POWDERS WERE OBTAINED FROM COMMERCIAL CARTRIDGES, AND ONE WAS A RELOADING POWDER. SAMPLES WERE ANALYZED BY USING GAS CHROMATOGRAPHY AND MASS SPECTROMETRY TECHNIQUES WITH DIFFERENTIALLY PUMPED CHEMICAL IONIZATION SOURCES. SAMPLES WERE INTRODUCED INTO THE MASS SPECTROMETER BY USING A HEATED SOLID PROBE INLET. FOR GAS CHROMATOGRAPHY ANALYSIS, SAMPLES WERE DISSOLVED IN REAGENT-GRADE ACETONE AND ANALYZED BY GAS CHROMATOGRAPHY-MASS SPECTROMETRY. FIVE MAJOR CONSTITUENTS WERE IDENTIFIED BY SPECTRAL ANALYSIS: NITROGLYCERIN; 2,4-DINITROTOLUENE; DIPHENYLAMINE; DIBUTYL PHTHALATE; AND ETHYL CENTRALITE. SLOW HEATING OF SMOKELESS POWDER PARTICLES IN THE MASS SPECTROSCOPY SOLID PROBE INLET DID NOT RESULT IN THE DETECTION OF ANY OF THE FIVE MAJOR VOLATILE COMPONENTS FROM A NITROCELLULOSE MATRIX. THE RESULTS SHOW THAT THERE IS NO SIMPLE WAY TO PREDICT THE COMPOSITION OF A SMOKELESS POWDER BASED ON CALIBER OR BULLET TYPE. SEVERAL PRECAUTIONARY POINTS ARE MADE IN RELATION TO THE ANALYSIS OF RESIDUAL POWDER: (1) IDENTIFICATION REQUIRES THAT POWDER RESIDUE FOUND AFTER FIRING BE CHEMICALLY IDENTICAL TO THE VIRGIN POWDER AND NOT HAVE LOST ONE OR MORE COMPONENTS BY SELECTIVE VOLATILIZATION; (2) POWDER PARTICLES MAY BE CONTAMINATED WITH RESIDUE FROM A PREVIOUS FIRING OF A GUN WITH A DIFFERENT AMMUNITION PREVENTING IDENTIFICATION; AND (3) IDENTIFICATION PRESUPPOSES KNOWLEDGE OF WHETHER A MANUFACTURER REGULARLY USES ONLY ONE KIND OF POWDER FOR EACH PARTICULAR CALIBER/BULLET COMBINATION. SUPPORTING DATA ARE TABULATED, AND REFERENCES ARE INCLUDED. (DP)

Downloads

No download available

Availability