scholarly journals Detection of Gunshot Residues Using Mass Spectrometry

2014 ◽  
Vol 2014 ◽  
pp. 1-16 ◽  
Author(s):  
Regina Verena Taudte ◽  
Alison Beavis ◽  
Lucas Blanes ◽  
Nerida Cole ◽  
Philip Doble ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Gold Standard ◽  
High Selectivity ◽  
Gunshot Residue ◽  
Chromatographic System ◽  
Gunshot Residues ◽  
X Ray ◽  
Metal Free ◽  
Forensic Scientists ◽  
Scanning Electron

In recent years, forensic scientists have become increasingly interested in the detection and interpretation of organic gunshot residues (OGSR) due to the increasing use of lead- and heavy metal-free ammunition. This has also been prompted by the identification of gunshot residue- (GSR-) like particles in environmental and occupational samples. Various techniques have been investigated for their ability to detect OGSR. Mass spectrometry (MS) coupled to a chromatographic system is a powerful tool due to its high selectivity and sensitivity. Further, modern MS instruments can detect and identify a number of explosives and additives which may require different ionization techniques. Finally, MS has been applied to the analysis of both OGSR and inorganic gunshot residue (IGSR), although the “gold standard” for analysis is scanning electron microscopy with energy dispersive X-ray microscopy (SEM-EDX). This review presents an overview of the technical attributes of currently available MS and ionization techniques and their reported applications to GSR analysis.

scholarly journals A Covalent Organic Cage Compound Acting as a Supramolecular Shadow Mask for the Regioselective Functionalization of C60

2020 ◽  
Author(s):  
Viktoria Leonhardt ◽  
Stefanie Fimmel ◽  
Ana-Maria Krause ◽  
Florian Beuerle
Keyword(s):  
Mass Spectrometry ◽  
Single Crystal ◽  
High Selectivity ◽  
Shadow Mask ◽  
X Ray Diffraction ◽  
X Ray ◽  
Trigonal Bipyramidal ◽  
Cage Compound ◽  
Vis Spectroscopy ◽  
Regioselective Functionalization

<div><div><div><p>A trigonal-bipyramidal covalent organic cage compound serves as an efficient host to form stable 1:1-complexes with C60 and C70. Fullerene encapsulation has been comprehensively studied by NMR and UV/Vis spectroscopy, mass spectrometry as well as single-crystal X-ray diffraction. Exohedral functionalization of encapsulated C60 via threefold Prato reaction revealed high selectivity for the symmetry-matched all-trans-3 addition pattern.</p></div></div></div>

scholarly journals An XRD, SEM and TG study of a uranopilite from Australia

2006 ◽  
Vol 70 (3) ◽  
pp. 299-307 ◽  
Author(s):  
R.L. Frost ◽  
M.L. Weier ◽  
G.A. Ayoko ◽  
W. Martens ◽  
J. Čejka
Keyword(s):  
Electron Microscopy ◽  
Mass Spectrometry ◽  
Northern Territory ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Evolved Gas ◽  
X Ray ◽  
Temperature Range ◽  
Step Over ◽  
Scanning Electron

AbstractA uranopilite from The South Alligator River, Northern Territory, Australia, has been studied using X-ray diffraction (XRD), scanning electron microscopy (SEM) with EDAX attachment, and thermogravimetry in conjunction with evolved gas mass spectrometry. The XRD shows that the mineral is a pure uranopilite with few if any impurities. The SEM images show that the uranopilite consists of elongated crystals, up to 50μm long and 5 μm wide. Thermogravimetry combined with mass spectrometry shows that dehydration occurs at ∼31°C resulting in the formation of metauranopilite. The first dehydration step over 20–71°C corresponds to a decrease of 5.4 wt.%, equivalent to 6.076 H2O. The second dehydration step, over the temperature range 71 –162.4°C corresponds to a decrease of 4.7 wt.%, equivalent to 5.288 H2O, making a total of 11.364 moles of H2O, close to 12 H2O for uranopilite.Dehydroxylation takes place over the temperature range 80–160°C. The loss of sulphate occurs at higher temperatures in two steps at 622 and 636°C. A mass loss also occurs at 755°C, accounted for by evolved oxygen.

Chemical and Morphological Study of Gunshot Residue Persisting on the Shooter by Means of Scanning Electron Microscopy and Energy Dispersive X-Ray Spectrometry

2011 ◽  
Vol 17 (6) ◽  
pp. 972-982 ◽  
Author(s):  
Zuzanna Brożek-Mucha
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Probability Of Detection ◽  
Energy Dispersive ◽  
Gunshot Residue ◽  
Time Intervals ◽  
X Ray ◽  
Irregular Shapes ◽  
The Face ◽  
Scanning Electron

AbstractPersistence of gunshot residue (GSR) simultaneously collected from hands, face and hair, and clothing of the shooting person was examined. Samples were collected from five shooters in nine time intervals after a single shoot with a Luger 9 mm pistol, in the range of 0–4 h and examined with scanning electron microscopy and energy dispersive X-ray spectrometry. Numbers of particles, frequencies of occurrence of certain compositions of particles, and their sizes in function of the time intervals were inspected. The greatest numbers of particles were observed in samples collected from hands right after shooting, but they decrease quickly with time. In samples collected from the face smaller initial numbers of particles were found, but they lasted at a similar level longer. The estimated half-life times of particles were less than 1 h for samples taken from the hands, over 1 h for clothing and about 2–3 h for the face. In samples collected at longer intervals after shooting, there were particles present of small sizes and irregular shapes. The results demonstrate that including evidence collected from the suspect's face and hair may increase the probability of detection of GSR in cases when the suspect has not been apprehended immediately after the investigated incident.

Evaluation of Concentration Techniques For Small Populations of Gunshot Residue (GSR) Particles Using Calibrated GSR Suspensions

1985 ◽  
Vol 43 ◽  
pp. 130-131 ◽  
Author(s):  
A. Zeichner ◽  
H. A. Foner ◽  
M. Dvorachek
Keyword(s):  
Small Area ◽  
Gunshot Residue ◽  
Small Populations ◽  
X Ray ◽  
Comprehensive Search ◽  
Size And Morphology ◽  
Time Required ◽  
Effective Use ◽  
Scanning Electron ◽  
Made In

It is generally accepted that the best method for the identification of GSR is by scanning electron microscopy with energy dispersive x-ray analysis (SEM-EDX), a technique which utilizes not only the chemical composition of the particles but also their size and morphology. Nevertheless, there remain many problems in the effective use of this technique.The main problem is the length of time required to conduct a comprehensive search for GSR in the samples as presented to the SEM. Attempts to solve this problem have been made in two main directions: (1) Concentration of the GSR after sampling onto a small area concomittant with some sort of treatment to remove extraneous interfering matter, and (2) computer-aided mechanization of the searching procedure. The latter approach is still in its very early experimental stages, whilst the methods used in the second approach are in need of further improvement. In particular, there has been no quantitative work on the efficiency of various concentration processes when using very small populations of GSR.

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