Gunshot residue analysis

Ruch et al. [26, 27] applied neutron activation analysis to the determination of barium and antimony deposited on the hands following the discharge of a gun. Table 6 lists the typical amounts of these elements removed from the back of the hand after a single firing of the weapon [23]. 

TYPICAL AMOUNTS OF BARIUM AND ANTIMONY DEPOSITED ON THE HAND AFTER A SINGLE FIRING OF VARIOUS FIREARMS 

The main problem associated with the application of gun-shot residue analysis is in the interpretation of the results. Lead is a ubiquitous contaminant of the environment, and little reliance can be placed on the presence of lead removed from the hand of a suspect. Barium and antimony are less commonly found in normal control samples however these elements can be present in hand swabs due to metal working, painting and other normal occupations. Also, the suspect must be apprehended soon after the incident and the swabs taken before the hands are washed. Nesbitt et al. [24] 

A representative sample of the gunshot residue is obtained by swabbing the thumb, web and forefinger with a cotton swab moistened with 1M nitric acid. The barium and antimony is leached from the cotton tip by soaking it in 1 or 2 ml of 5% (v/v) nitric acid. Instrumentation Laboratory [30] recommend the neutralisation of the solution by the addition of 0.2 ml concentrated ammonium hydroxide solution. 

INSTRUMENT PARAMETERS FOR BARIUM ANALYSIS OF GUNSHOT RESIDUES (HEATED GRAPHITE FURNACE) 

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L. S. Leggett, and P. F. Lott, Gunshot Residue Analysis via Organic Stabilizers and Nitrocellulose, Microchemical Journal 39 (1989) 76. 

Bueno, J., Sikirzhytski, V., Lednev, I.K. Attenuated total reflectance-FT-IR spectroscopy for gunshot residue analysis potential for ammunition determination. Anal. Chem. 85,7287-7294 (2013)... 

Meng H and Caddy B (1997) Gunshot residue analysis - a review. Journal of Forensic Sciences 42 553. 

Schwoehle AJ and Exline DL (2000) Current Methods in Forensic Gunshot Residue Analysis. Boca Raton, FL CRC Press. 

D. "Gunshot Residue Analysis by Micellar Electrokinetic Capillary Electrophoresis Assessment for ApplicaHon to Casework" (Parts 1 and 2). Journal cf Forensic Sciences 46 (2001), 549-572. 

Standard Guide for Gunshot Residue Analysis Scanning Election Microscopy/Energy-CHspersive Sp>ec-... 

A Del Electronics, Model ESP-100A, electrostatic precipitator was used for sample collection. Cigarette smoke particles were found to give approx the same particle distribution pattern on the collection filter paper as the gunshot residue, and since the smoke stains the paper, this provided a v rapid technique for optimizing operation conditions. With a flow rate of 15cfm and a corona current of 125 uA, the residue collects primarily on a narrow band across the sample paper. Samples were collected on Whatman No 1541 filter paper which lined the inside of the sample collection tube. The presence of this paper allowed air to flow only thru the center of the tube, so particle collection was made upon the filter paper exclusively. The filter paper samples were pelletized prior to neutron activation analysis... 

Sb and Ba are present in the airborne gunshot residue expelled from all of the brands of 0.22 cal ammo. A chemical analysis of the primer. of the Western brand gave a Ba to Sb ratio of 65, whereas the same ratio obtained from the data in Table 11 is 2.6. The authors conjecture that this additional Sb left in the air came from the vaporized bullet Pb which contains a large amt of Sb as a hardening agent... 

A Comparison of Neutron Activation Analysis and Atomic Absorption Spectroscopy on Gunshot Residue... 

Guinn, V. P. "The Determination of Traces of Barium and Antimony in Gunshot Residue by Activation Analysis" Gulf General Atomic Report GA 8171 San Diego, (1967)... 

Guinn, V. P. et. al., Special Report on Gunshot Residue measured by Neutron Activation Analysis, Gulf-General Atomic Report GA 9829, August 10, 1970... 

I describe here the results of our preliminary study (22) of the application of photoluminescence techniques to gunshot residue detection. The key objective in this study was to develop a rapid, reliable, and convenient method of detection for use in the crime laboratory on the basis of the detection of lead, antimony, and barium. We did not attempt to repeat the extensive work already carried out with neutron activation analysis concerning the importance of the detection of these elements and the interpretation of findings. The literature concerning photoluminescence was surveyed for methods of analysis for antimony, barium, and lead that would be (a) reliable, sensitive, and quantitative ... 

Hackleman, R. P., and Korts, R. F., "Special Report on Gunshot Residues Measured by Neutron Activation Analysis, Gulf General Atomic, Inc., San Diego, 1970. 

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