organic gunshot residue from lead-free ammunition

243 Pages·2005·15.66 MB·English

FACULTE DE DROIT
ECOLE DES SCIENCES CRIMINELLES
INSTITUT DE POLICE SCIENTIFIQUE

ORGANIC GUNSHOT RESIDUE FROM

LEAD-FREE AMMUNITION

THESE DE DOCTORAT

Présentée à l’Institut de Police Scientifique
de l’Université de Lausanne

par

FRANCESCO SAVERIO ROMOLO

Diplômes en chimie et en pharmacie
Université “La Sapienza” de Rome

Lausanne 2004

Acknowledgements
I am deeply grateful to Prof. Pierre Margot, director of the “Ecole des Sciences Criminelles” of the
University of Lausanne, for supervising my project and for helping me during the course of the
research with his suggestions and constructive criticism. I wish to thank Prof. Michael Lederer who
suggested applying for the PhD in Lausanne. The experimental part of this study was initially
conducted in the laboratories of the Italian Forensic Science Service and terminated in the
"Laboratorio per la Sicurezza" of the Università degli Studi di Roma "La Sapienza". During the
course of the research project I spent some wonderful times in the Forensic Science Agency of
Northern Ireland, where I learned sampling procedures and I had interesting discussions with Jim
McQuillan, David Brooks and Ann Irwin in 1998. Another great experience was my internship in
the Division of Identification and Forensic Science of the Israel Police in 1999, where I met Joseph
Almog, Nadav Levin, Tsippi Tamiri, Arie Zeichner, Shmuel Zitrin and I learned a lot more about
explosive trace detection and analysis of GSR. I wish to thank Jan Andrasko, Lawrence
Gunaratnam, Robin Keeley and Ludwig Niewöhner for the fruitful discussions during the meetings
of the Firearms Working Group of the European Network of the Forensic Science Institutes. I am
also grateful to the colleagues of the "Ecole des Sciences Criminelles" of Lausanne, who supported
me and helped me during the shooting tests and the analysis of samples. I have particularly
appreciated the hospitality of Prof. Geneviève Massonet and Prof. Olivier Ribaux, who patiently
hosted me in their room in the “Ecole des Sciences Criminelles”. I would like to thank Prof. Carlo
Torre, of the University of Turin, for the analyses by SEM-EDX. Last but not least, I wish to thank
the jury, Prof. Joseph Almog, Prof. Brian Caddy, Dr. Alain Gallusser and Prof. Pierre Margot for
encouraging my research.

TABLE OF CONTENTS

PART ONE
PRELIMINARY REMARKS

I. Introduction

p.1

II. Aim of the research
p.4

III. Structure of the research
p.8

PART TWO
EXPERIMENTAL PART

IV. The analysis of smokeless powder in lead-free
ammunition
p.11

4.1. Introduction p.11
4.2. Experimental p.11
4.2.1. Chemicals and reagents p.11
4.2.2. Equipment p.16
4.2.3. Sample preparation p.16
4.3. Results and discussion p.17

V. Shooting tests and sampling procedures
p.25

5.1. Introduction p.25
5.2. Experimental p.31
5.2.1. Materials and equipment p.31
5.2.2. Shooting tests p.32
5.2.3. Sampling procedures p.35
5.2.3.1. Sampling procedures for skin surfaces p.37
5.2.3.2. Sampling procedures for clothes p.37
5.2.4. Sample preparation p.37
5.2.4.1 Preparation of swabs from skin surfaces p.37
5.2.4.2 Preparation of filters from clothes p.41

I
5.3. Results and discussion p.44
5.3.1. Cotton pads for swabs p.44
5.3.2. Solvent recovery from filters p.46

VI. Analysis with ion mobility spectrometry
p.47

6.1. Introduction p.47
6.2. Experimental p.52
6.2.1. Chemicals and reagents p.52
6.2.2. Equipment p.52
6.2.3. IMS analysis p.53
6.3. Results and discussion p.55

VII. Analysis with EGIS
p.63

7.1. Introduction p.63
7.2. Experimental p.64
7.2.1. Chemicals and reagents p.64
7.2.2. Equipment p.64
7.2.3. EGIS analysis p.64
7.3. Results and discussion p.65

VIII. Analysis with HPLC-MS-MS
p.70

8.1. Introduction p.70
8.2. Experimental p.70
8.2.1. Chemicals and reagents p.70
8.2.2. Equipment p.71
8.3. Results p.72
8.3.1. HPLC analysis p.72
8.3.2. MS analysis p.73
8.3.3. Chromatography and mass spectrometry p.86
8.3.4. Limits of detection p.91
8.3.5. Linearity p.93
8.3.6. Accuracy and precision p.99
8.3.7. Recoveries p.102
8.3.7.1. Recoveries from swabs p.102
8.3.7.2. Recoveries from filters p.109
8.3.7.3. Recoveries from hands p.114
8.3.8. Analysis of samples from shooting tests p.117
8.3.9. Analysis of possible sources of DPA p.129
8.4. Discussion p.130

II
IX. Discussion
p.132

9.1. Chemical interpretation of the analytical results p.132
9.1.1. Diagnostic sensitivity of Ionscan and EGIS p.133
9.1.2. Analysis with HPLC-MS-MS p.136
9.2. Forensic significance of the analytical results p.141
9.2.1. Interpretation of results from clothes in a forensic perspective p.143
9.2.2. Interpretation of results from hands in a forensic perspective p.147

X. Conclusions
p.151

ANNEXES

Annexe 1 Historical introduction on firearms ammunition p.154

Annexe 2 The explosives in ammunition p.162
A. Explosions and explosives p.162
A.1. Definitions p.162
A.2. Characteristics of explosives p.163
A.3. Factors influencing an explosion p.164
B. Initiating explosives and primers p.165
B.1. Initiating explosives p.165
B.2. Primer mixtures: from the beginning to corrosive-free p.166
B.3. Lead-free primers p.169
C. Propellants p.171
C.1. Black powder and smokeless powders p.171
C.2. Stabilizers p.173
C.3. Other additives p.175

Annexe 3 SEM-EDX analyses of GSR p.181

Annexe 4 X-rays diffraction (XRD) analyses of primers p.186

Annexe 5 Analysis of explosives p.189
A. Introduction p.189
B. Clean-up techniques p.191
C. Chromatographic analysis p.196
D. Mass spectrometric analysis p.208
E. Capillary electrophoresis and electrochromatography p.214

Annexe 6 API 3000 p.217

REFERENCES
p.220
III

Introduction

I.

Introduction

The analysis of gunshot residue (GSR) often provides crucial information in criminal investigation.
Detection and identification of GSR are commonly performed with the aim of determining whether
or not a person fired a gun. GSR are composed of burned and unburned particles from the propulsive
charge, as well as components from the primer, the bullet, all the other components of the cartridge
(see annexes 1 and 2) and the firearm itself.
The scanning electron microscope equipped with an energy dispersive X-ray analyser (SEM-EDX)
can isolate and help identify individual gunshot residue particles through both morphological and
elemental characteristics. The morphology and the chemical composition of particles produced by
the explosion of cartridges containing lead, antimony and barium in the primer are distinctive.
Wolten et al. [1979] and later Wallace and McQuillan [1984] proposed to classify GSR particles in
categories, based on their possible sources. The GSR particle whose only known source is the
explosion of a primer mixture were called “unique” particles by Wolten et al. [1979].
In 1982, Hagel and Redecker patented a primer used for the manufacturing of a new ammunition,
developed to minimize airborne lead levels and possibly other metallic residue such as barium and
antimony [Hagel and Redecker, 1982]. The new ammunition was called SINTOX® and was
commercialized by Dynamit Nobel. The primers for this kind of ammunition are produced without
the elements presents in the “unique” particles (lead, barium, antimony) and their explosion does not
produce “unique” or specific particles. Therefore the contribution of SEM-EDX analysis can be poor
in forensic cases when such cartridges are used [Romolo and Margot, 2001], while organic GSR
detection could be fundamental in criminal cases when lead-free ammunition is shot. Some
1
Introduction

SEM-EDX analyses of particles produced by lead-free primers are collected in annexe 3. In annexe 4
there are the X-ray diffraction analyses of a traditional primer (containing antimony sulphide, barium
nitrate and lead styphnate) and of a lead-free primer (containing diazodinitrophenol and strontium
nitrate).
The organic gunshot residue (O-GSR) is mainly the residue of the propellant contained in the
cartridge. Propellants used in cartridges are known as smokeless powders. They are essentially low
explosives, in that they have a reaction rate slow enough to allow its use as a propellant for
projectiles. Smokeless powders are either single-base (nitrocellulose), double-base (nitrocellulose
plus nitroglycerine) or triple-base (nitrocellulose, nitroglycerine, nitroguanidine) [Meyer et al.,
2002]. In propellant manufacturing one or more stabilizers are always employed, due to their
chemical structure which prevents the spontaneous, exothermic and acid-catalyzed decomposition of
nitrocellulose, nitroglycerine and similar nitric acid esters. Diphenylamine (DPA) reacts with the
oxides of nitrogen formed by the slow decomposition of the nitrocellulose (NC), thereby being
converted into the corresponding N-nitroso and nitro-derivates. DPA is a pure stabilizer, while other
substances, such as methylcentralite (MC) and ethylcentralite (EC), can exert both a stabilizing effect
and a gelatinizing effect, simplifying the manufacturing of smokeless powders. Other compounds are
introduced into propellant formulations for specific purposes, among them dinitrotoluenes are used
as burn modifiers and phthalates as plasticizers (see annexe 2).
The analysis of diphenylamine, methylcentralite, ethylcentralite or others stabilizers and their
degradation products in bulk propellants permit the study of the behaviour of propellants during
ageing and the estimation of the probable shelf life of the powder. Another aspect of the separation
and identification of stabilizers and their reaction products in smokeless powders can be the
characterization of a sample for forensic purposes, because these derivatives reflect not only the
production of the gunpowder, but also its storage conditions and thermal history following
manufacture [Espinoza and Thornton, 1994]. Smokeless powders are commonly used to prepare
2