A qualitative comparison of smokeless powder measurements

In the spring of 2000, the National Institute of Standards and Technology and nineteen participants conducted a comparison of smokeless powder additive compositional measurements. The purpose of this exercise was to determine the state-of-the-practice for forensic smokeless powder determinations. For the comparison, two handgun reloading powder samples were mixed and were compositionally evaluated for homogeneity by NIST. Participant laboratories included military, academic, and state/local, federal, and international forensic agencies. We solicited qualitative data identifying nitroglycerin, diphenylamine, N-nitrosodiphenylamine, and ethyl centralite. In addition, some laboratories provided identification of additional ingredients, such as nitrocellulose, or reported other measurements, such as dimensional morphology. In this paper, laboratory identification of the smokeless powder additives and a summary of the measurement methods used for the evaluations are presented. All laboratories correctly identified NG and the major stabilizers. Some disparity between laboratories was noted for the identification of minor (<0.01% by weight) stabilizers and stabilizer decomposition products.     

Comparing the additive composition of smokeless gunpowder and its handgun-fired residues

Detecting the use of handguns via the determination of the organic additives in smokeless gunpowder residues (OGSR) presents a promising alternative to primer metal residue analysis. Compositional analysis of the gunpowder additives nitroglycerin, diphenylamine, and ethyl centralite provides information that can associate residue samples with unfired gunpowder. We evaluated the composition of seven reloading smokeless gunpowders, both in bulk and as single particles, by ultrasonic solvent extraction/capillary electrophoresis. Handgun-fired residues obtained from three common weapon calibers loaded with the known reloading powders were compared with the unfired powders. In general, the composition of the residues was similar to that found in the unfired powders. For double-base powders, comparing the ratio of the propellant (P) to the total amount of stabilizer (S) for both residue and gunpowder samples proved to be a useful measurement for identification. This P/S ratio demonstrated that the additives in the residues did not greatly change relative to the unfired powder, providing a useful indicator to aid in forensic powder and residue evaluation.     

Associating gunpowder and residues from commercial ammunition using compositional analysis

Qualitatively identifying and quantitatively determining the additives in smokeless gunpowder to calculate a numerical propellant to stabilizer (P/S) ratio is a new approach to associate handgun-fired organic gunshot residues (OGSR) with unfired powder. In past work, the P/S values of handgun OGSR and cartridges loaded with known gunpowders were evaluated. In this study, gunpowder and residue samples were obtained from seven boxes of commercial 38 caliber ammunition with the goals of associating cartridges within a box and matching residues to unfired powders, based on the P/S value and the qualitative identity of the additives. Gunpowder samples from four of the seven boxes of ammunition could be easily differentiated. When visual comparisons of the cartridge powders were considered in addition to composition, powder samples from all seven boxes of ammunition could be reliably differentiated. Handgun OGSR was also collected and evaluated in bulk as well as for individual particles. In some cases, residues could be reliably differentiated based on P/S and additive identity. It was instructive to evaluate the composition of individual unfired gunpowder and OGSR particles. We determined that both the numerical centroid and dispersity of the P/S measurements provide information for associations and exclusions. Associating measurements from residue particles with those of residue samples collected from a test firing of the same weapon and ammunition appears to be a useful approach to account for any changes in composition that occur during the firing process.     

Developing a quantitative extraction technique for determining the organic additives in smokeless handgun powder.

Compositional analysis of the organic additives in smokeless handgun powder can provide forensic information to associate known and questioned samples. A reliable method for the quantitative extraction of smokeless powder additives would strengthen these measurements. To achieve quantitative recovery, both supercritical fluid extraction (SFE) and ultrasonic solvent extraction (USE) were evaluated as candidate techniques. Following a detailed evaluation of the solvent choice, the recovery of spiked additive compounds, and the effect of the powder matrix, a reliable USE technique was developed. When quantitative USE recovery of the target analytes, nitroglycerin (NG), diphenylamine (DPA), and ethyl centralite (EC), is coupled with additive measurement by micellar capillary electrophoresis (CE), compositional information can be obtained in less than 1 h.     

Characterization of gunpowder samples using time-of-flight secondary ion mass spectrometry (TOF-SIMS)

Time-of-flight secondary ion mass spectrometry (TOF-SIMS) was utilized to obtain characteristic mass spectra from three different smokeless powders and six different black powder samples. In these mass spectra, peaks indicative of both the organic and inorganic additive constituents in the gunpowders were observed. TOF-SIMS was able to successfully differentiate between the different black and smokeless gunpowder samples analyzed with the aid of principal components analysis (PCA), a multivariate statistical analysis approach often used to reduce the dimensionality of complex data. TOF-SIMS was also used to obtain information about the spatial distribution of the various additives contained within the gunpowder samples. SIMS imaging demonstrated that that the samples could potentially be characterized by their 2-D structure, which varied from sample to sample. These results clearly demonstrate the feasibility of utilizing TOF-SIMS as a tool for the characterization and differentiation of gunpowder samples for general forensic applications.     

Investigating the effect of changing ammunition on the composition of organic additives in gunshot residue (OGSR)

The measurement of the organic additives in smokeless gunpowder is an attractive approach for the detection of handgun use because it provides compositional information that can help associate residues and unfired gunpowder. We investigate several factors that will be required to advance the characterization of organic gunshot residue (OGSR) as a useful forensic tool, including evaluating residue contamination from previously fired ammunition, particle-to-particle compositional variability, and compositional features resulting from the type of firing primer used. Using ammunition loaded with known smokeless powders containing different stabilizers, a sequence of shots was fired from a .357 magnum revolver, and the muzzle exit residues were collected. Compositional analysis of the residues, both in bulk and as single particles, showed only a trace of the previously fired powder in the first shot and none in subsequent shots. In an additional experiment testing conventional leaded and the new lead-free firing primers, the OGSR composition was found not to depend on the primer type.     

Detection of gunpowder stabilizers with ion mobility spectrometry

This study is the first reported ion mobility detection of ethyl centralite and diphenylamine (DPA) smokeless gunpowder stabilizers, together with the nitroso and nitro derivatives of diphenylamine. First, the applicability of the ion mobility spectrometry (IMS) for the substances of interest was determined. The existence of numerous peaks, both in positive and negative modes, clearly demonstrates the success of these experiments. All mono and di-nitro derivatives of DPA tested were detected with this method. Unfortunately, many of the ions generated were not accurately identified. However, reduced mobility constants representative of each ion generated under defined operating conditions could be used for purpose of compound identification. The method was then successfully tested on real gunpowder samples. By the use of IMS, we managed to establish a rapid, simple and sensitive screening method for the detection and identification of smokeless gunpowder organic components.     

Vacuum collection of gunpowder residues from clothing worn by shooting suspects, and their analysis by GC/TEA, IMS, and GC/MS

Experiments were conducted to collect gunpowder (propellant) residues from shooters' clothing by vacuum and to analyze them by gas chromatography/thermal energy analyzer (GC/TEA), ion mobility spectrometry (IMS), and gas chromatography/mass spectrometry (GC/MS). The residues were collected on fiberglass and Teflon filters using the portable vacuum sampler, all supplied with the IMS instrument. Several solvents were examined for the extraction of the propellant components from the filters. The extracts were centrifuged and/or filtered, concentrated by evaporation, and analyzed without any additional clean-up procedure. Based on the results of the study, an operational method for analysis of gunpowder residues was introduced into casework without changing the present operational technique for gunshot (primer) residue (GSR) analysis on clothing implemented by the Israel Police. In the modified method, the clothing is first sampled by double-side adhesive-coated aluminum stubs (the tape-lift method) for GSR analysis (the existing method), followed by vacuum collection for propellant residue examination. The issue of interpretation of the analytical results is discussed.     

A novel method for extraction and analysis of gunpowder residues on double-side adhesive coated stubs

A study was conducted to develop an efficient method for extraction and analysis of gunpowder (propellant) residues from double-side adhesive coated stubs, which are used for sampling suspects or their clothing for gunshot (primer) residues (GSR). Conductive and non-conductive double-side adhesives were examined, and the analysis was carried out by gas chromatography/thermal energy analyzer (GC/TEA) and ion mobility spectrometry (IMS). The optimal procedure for the extraction, as was developed in the present study, employs two stages: (1) extraction of the stubs with a mixture of 80% v/v aqueous solution of 0.1% w/v of sodium azide and 20% v/v of ethanol employing sonication at 80 degrees C for 15 min. and (2) residues from the obtained extract were further extracted with methylene chloride. The methylene chloride phase was concentrated by evaporation prior to analysis. Extraction efficiencies of 30-90% for nitroglycerine (NG) and for 2,4-dinitro toluene (2,4-DNT) were found. No significant interferences in the analysis were observed from the adhesives or skin. Interferences were observed in the analysis by the GC/TEA of the samples collected from hair. The method enables analysis of propellant residues on a double-side adhesive coated stub after it was examined for primer residues by scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDX). Thus, the probative value of the evidence may be increased.     

A novel method for the analysis of discharged smokeless powder residues

A novel method for the estimation of intermediate-long firing distance range is proposed. The method is based on the characterization and chemical analysis of the smokeless powder particles on the target. An adhesive lifter is applied to collect the suspected gunshot residues (GSRs) from the surface of an object, and a Modified Griess Test (MGT) is carried out after alkaline hydrolysis on the adhesive lifter. Visualized particles are removed from the adhesive lifter under a microscope. Two systems are used for the analysis of organic discharge residues from the smokeless powder: (1) gas chromatography/thermal energy analysis (GC/TEA) for the analysis of nitroglycerine (NG) and 2,4-dinitrotoluene (2,4-DNT), (2) gas chromatography/mass spectrometry (GC/MS) for the identification of organic components such as DNT, NG, and some stabilizers. By using this procedure and confirming that the suspected particles are indeed GSR, one can estimate the intermediate-long firing distance of c. 0.75-3 m in the presence of very few particles and provide information for the classification of ammunition type in casework.     

A comparison of smokeless powders and mixtures by capillary zone electrophoresis

The analysis of inorganic ions present in smokeless and muzzleloading powders has been performed using capillary zone electrophoresis (CZE). Previous publications have examined inorganic low explosives using CZE, but have not looked at the ion profiles from smokeless powders. In this report, seven commercially available smokeless powders were analyzed as unburned powder and burned residue. The results demonstrate that ionic profiles can be used to characterize smokeless powders. Our analysis also included a smokeless powder/ Pyrodex combination to determine if smokeless powder ions are distinguishable in a mixture; however, the high concentration of ions present in Pyrodex RS prevented its detection. In addition, five different smokeless powder samples as well as Pyrodex RS were collected for analysis subsequent to deflagration in fifteen plastic pipe bombs. The relative ion concentrations between these powders can be used to illustrate the differences between open burning and pipe bomb deflagration.     

Mobile phase influence on electrospray ionization for the analysis of smokeless powders by gradient reversed phase high-performance liquid chromatography-ESIMS

The solution parameters associated with gradient elution reversed phase high-performance liquid chromatography (HPLC) were characterized by evaluating the electrospray ionization mass spectrometry (ESIMS) response of selected smokeless powder additives. Using direct liquid infusion, the positive ion ESIMS responses were determined for three general classes of powder constituents: dialkylphthalate acid esters, N,N'-dialkyl-N,N'-diphenyl urea based stabilizers and nitroso-, nitro-, and dinitro- derivatives of diphenylamine. The relative ESIMS intensities of the powder components were investigated as a function of three solution parameters: ammonium acetate concentration, pH, and percent methanol. The effect of the ammonium acetate concentration demonstrates that the electrolyte is required for efficient ionization and the ESIMS intensity was optimal at a concentration of 2mM for the selected compounds, except 2,4'-dinitrodiphenylamine. The aqueous solution pH, corresponding to the available protons in solution, did not have a significant effect on the ESIMS intensity of the analytes. The percent methanol was evaluated with both decreasing and constant electrolyte concentrations to demonstrate the effects of droplet stability and ion transfer into the gas phase. These findings were applied to the analysis of the selected smokeless powder additives using HPLC-ESIMS to illustrate increased sensitivity for the protonated molecules.     

Lessons learned from inter-laboratory studies of carbon isotope analysis of honey

Forensic application of carbon isotope ratio measurements of honey and honey protein to investigate the degree of adulteration with high fructose corn syrup or other C₄ plant sugars is well established. These measurements must use methods that exhibit suitable performance criteria, particularly with regard to measurement uncertainty and traceability – low levels of adulteration can only be detected by methods that result in suitably small measurement uncertainties such that differences of 1‰ or less can be reliably detected. Inter-laboratory exercises are invaluable to assess the state-of-the art of measurement capabilities of laboratories necessary to achieve such performance criteria. National and designated metrology institutes from a number of countries recently participated in an inter-laboratory assessment (CCQM-K140) of stable carbon isotope ratio determination of bulk honey. The same sample material was distributed to a number of forensic isotope analysis laboratories that could not participate directly in the metrological comparison. The results from these studies have demonstrated that the majority of participants provided isotope delta values with acceptable performance metrics; that all participants ensured traceability of their results; and that where measurement uncertainties were reported; these were fit-for-purpose. A number of the forensic laboratories only reported precision rather than full estimates of measurement uncertainty and this was the major cause of the few instances of questionable performance metrics. Reporting of standard deviations in place of measurement uncertainties is common practice outside metrology institutes and the implications for interpretations of small differences in isotopic compositions are discussed. The results have also highlighted a number of considerations that are useful for organisers of similar inter-laboratory studies in the future.     

DART-TOFMS法检测发射药中的硝化甘油和Ⅱ号中定剂

目的建立一种快速检测发射药中主要成分硝化甘油（NG）、Ⅱ号中定剂（C2）的方法。方法采用实时直接分析飞行时间质谱技术（DART-TOFMS）,在正负离子模式下,通过特征分子离子精确质量数进行检材中NG和C2的定性分析。结果 NG的检测限为0.044mg/L,C2的检测限为0.0032 mg/L,检测时间仅在1min以内。结论该方法无需样品前处理和预分离,且具有快速、不受样品存在形态限制等优点,已用于案件检验,为案件的快速侦破发挥了重要的作用。     

Comparison of bulk and compound-specific δ13C isotope ratio analyses for the discrimination between cannabis samples

Five marijuana samples were compared using bulk isotope analysis compound-specific isotope ratio analysis of the extracted cannabinoids. Owing to the age of our cannabis samples, four of the five samples were compared using the isotope ratios of cannabinol (CBN), a stable degradation product of Δ(9)-tetrahydrocannabinol (THC). Bulk δ(13)C isotope analysis discriminated between all five samples at the 95% confidence level. Compound-specific δ(13)C isotope analysis could not distinguish between one pair of the five samples at the 95% confidence level. All the measured cannabinoids showed significant depletion in (13)C relative to bulk isotope values; the isotope ratios for THC, CBN, and cannabidiol were on average 1.6‰, 1.7‰, and 2.2‰ more negative than the bulk values, respectively. A more detailed investigation needs to be conducted to assess the degree fractionation between the different cannabinoids, especially after aging.     

Comparison of injuries caused by the pistols Tokarev, Makarov and Glock 19 at firing distances of 10, 15 and 25cm

Firings at cloth targets and at human skin from autopsy material were performed from the pistols 7.62 mm Tokarev (TT), 9 mm Makarov (PM) and 9 x 19 mm Glock 19 with common ammunition. The differences were in the soot deposit pattern, the degree of scorching of the synthetic fibres on the edges of the entrance hole and in the findings of the soot and the gunpowder particles. The results were similar on the cloth and on the skin targets. In the case of the TT and the PM, the soot deposit patterns reminded of a blossom or shafts of rays or fans, or the bullet wipe had four narrow and four wide sections regarding the number of lands and grooves. The TT left a large amount of soot and many gunpowder particles and caused the melting of the synthetic fibres on the edges of the entrance hole, producing a defect of the material 0.1-0.3 cm in diameter and defects of textile fibres around the entrance hole. In the skin the TT caused many intraepithelial tears, folds of the epidermis and recesses of the epidermis containing soot. Firings from the PM and the Glock 19 caused the melting only of the ends of individual synthetic fibres on the edges of the entrance hole. The PM left a large amount of soot and only a few gunpowder particles. The Glock 19 gave the least soot and the greatest number of gunpowder particles and also caused tears and recesses in the epidermis. Only in the case of the Glock 19, hexagonal or polygonal zones were seen in the soot deposit pattern. The differences in the soot pattern were more distinct at the firing distance of 10 cm. By increasing the distance from 10 to 15 cm, the intensity of soot diminished and began to disappear at 25cm, but remained more visible in the case of the TT. The gunpowder particles could be found in the epidermis and deeper in both layers of the dermis at all distances fired from the TT and the Glock 19. In the case of firings from the PM, at the distance 10 cm some of the gunpowder particles had penetrated into the dermis and most of them were in the upper layer of the dermis. At the firing distance of 15 and 25 cm, the gunpowder particles were only on and in the stratum corneum.     

Gunpowder particles as a factor in a gunshot from up close

Existence of different opinions on the role of gunpowder particles in determining close shot distance promoted the experiments with pistol "PM" and sporting fowling piece in vertical and horizontal directions at different distances from 0.5 up to 2.5 m using targets made of pasteboard and moistened photographic paper. The quantities of gunpowder particles on the targets which were calculated by stereoscopic microscope increased distinctly in vertical shot direction (from above downwards), especially at distances 2 and 2.5 m and particle flight distance rose; in horizontal shot direction distances of gunpowder particle flight didn't exceed 2-3 m.     

我国刑法应增设研发、生产、销售危害人体健康添加剂罪

"蛋白粉"、瘦肉精等危害人体健康的添加剂不属于食品,生产销售上述添加剂不能定性为生产销售有毒有害食品罪。研发、生产、销售危害人体健康的添加剂必须介入他人的有责行为才会发生危害社会结果,不宜定性为以危险方法危害公共安全罪。无相应合格产品存在或不属质量不合格的不能定性为生产销售伪劣产品罪。生产销售绝对不允许买卖产品不宜定性为非法经营罪,即使属于非法经营或生产销售伪劣产品也要达5万元以上才能入罪,无法规制会危害人体健康但数额未达5万元以上的行为。《刑法》规定的漏洞导致司法机关选择最相类似罪名定处有破坏罪刑法定原则的危险,故我国《刑法》应增设研发、生产、销售危害人体健康添加剂罪。     

Rifle wounds from high velocity, center-fire hunting ammunition.

Wounds inflicted by high velocity, center-fire rifles firing hunting ammunition are radically different from wounds caused by handguns or .22 rim-fire rifles. Injuries from pistol or .22 rim-fire bullets are confined to tissue and organs directly in the wound track. In contrast, high velocity rifle bullets can injure structures without actually contacting them. This is due to the temporary cavity produced by such missiles with the resultant shock waves having pressures of up to 200 atmospheres (20 MPa). Organs struck by such high velocity rifle bullets may undergo partial or complete disintegration. Hunting ammunition, as it passes through the body, tends to shed fragments of lead from its core, producing a characteristic snowstorm picture on X-ray. The maximum range at which powder tattooing of the skin occurs from center-fire rifles depends on the physical form of smokeless powder used as propellant. In a test with a 30-30 rifle, cartridges loaded with ball powder produced powder tattooing out to a range of 30 in. (76 cm), while similar cartridges, loaded with the traditional cylindrical powder, produced tattooing out to only 12 in. (30 cm) of range.     

A Study of the Presence of Gunshot Residue in Pittsburgh Police Stations using SEM/EDS and LC‐MS/MS

Due to possible secondary transfer of gunshot residue (GSR) onto a suspect in police custody prior to sampling, a baseline must be created for the amount of GSR present. With an increase of “lead free” ammunition, testing for both gunpowder and primer GSR is relevant. Seventy samples were collected using carbon‐coated adhesive stubs from four Pittsburgh Police Stations and vehicles to investigate these locations as sources of secondary GSR contamination. These seventy samples were analyzed for primer GSR using scanning electron microscopy‐energy‐dispersive X‐ray spectrometry. One primer GSR particle was detected; no sample was classified as positive for primer GSR. These same samples were then analyzed for gunpowder GSR using liquid chromatography coupled to tandem mass spectrometry to test for akardite II, ethylcentralite, diphenylamine, N‐nitrosodiphenylamine, 2‐nitrodiphenylamine, and 4‐nitrodiphenylamine. Ethylcentralite was quantifiable in two test samples. These results suggest there is a negligible potential for secondary transfer of primer and gunpowder GSR.