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1.
Designer psychostimulants are known by recreational drug users to produce a complex array of adrenergic and hallucinogenic effects. Many of these drugs are not targeted during routine toxicology testing and as a consequence, they are rarely reported. The purpose of this study was to develop a procedure for the detection of 15 psychostimulants in urine using liquid chromatography–tandem mass spectrometry (LC‐MS/MS), specifically 2,5‐dimethoxy‐4‐bromophenethylamine (2C‐B), 2,5‐dimethoxy‐4‐chlorophenethylamine (2C‐C), 2,5‐dimethoxy‐4‐methylphenethylamine (2C‐D), 2,5‐dimethoxy‐4‐ethylphenethylamine (2C‐E), 2,5‐dimethoxyphenethylamine (2C‐H), 2,5‐dimethoxy‐4‐iodophenethylamine (2C‐I), 2,5‐dimethoxy‐4‐ethylthiophenethylamine (2C‐T‐2), 2,5‐dimethoxy‐4‐isopropylthiophenethylamine (2C‐T‐4), 2,5‐dimethoxy‐4‐propylthiophenethylamine (2C‐T‐7), 2,5‐dimethoxy‐4‐bromoamphetamine (DOB), 2,5‐dimethoxy‐4‐chloroamphetamine (DOC), 2,5‐dimethoxy‐4‐ethylamphetamine (DOET), 2,5‐dimethoxy‐4‐iodoamphetamine (DOI), 2,5‐dimethoxy‐4‐methylamphetamine (DOM), and 4‐methylthioamphetamine (4‐MTA). Analytical recoveries using solid‐phase extraction were 64–92% and the limit of detection was 0.5 ng/mL for all drugs except 2C‐B (1 ng/mL). The assay was evaluated in terms of analytical recovery, precision, accuracy, linearity, matrix effect, and interferences. The technique allows for the simultaneous detection of 15 psychostimulants at sub‐ng/mL concentrations.  相似文献   

2.
Abstract: Pyrodex ® and Triple Seven ® are black powder substitutes that often find use as fillers in improvised explosive devices, such as pipe bombs. These propellants have essentially the same overall appearance and oxidizers, but different fuels. For example, Pyrodex ® contains sulfur, sodium benzoate, and dicyandiamide (DCDA), whereas Triple Seven ® lacks sulfur but also contains 3‐nitrobenzoic acid. In this method, intact particles and postblast solid residues were reacted with bis(trimethylsilyl)trifluoroacetamide + 1% trimethylchlorosilane in acetonitrile for 30 min at 60°C. The resultant trimethylsilyl derivatives of the organic fuels were then analyzed by gas chromatography–mass spectrometry. Each derivative was clearly resolved from other components, and high‐quality mass spectra were obtained. In addition, characteristic fragments resulting from loss of a methyl radical from the molecular ion (m/z 163 for sulfur, m/z 171 for DCDA, m/z 179 for benzoic acid, and m/z 224 for nitrobenzoic acid) were able to be monitored.  相似文献   

3.
The differing effects of weathering and microbial degradation are described here in a comprehensive study that involved 50 different ignitable liquids from the Ignitable Liquids Database and Reference Collection. Examples of ignitable liquid residues from each of the main classes established by the American Society of Testing and Materials are presented. Weathering was accomplished via evaporation, whereas microbial degradation was carried out on soil at room temperature for periods of up to 21 days. Major trends included the rapid degradation of long n‐alkanes and monosubstituted alkyl benzenes (e.g., toluene, ethylbenzene, and propylbenzene). Surprisingly, some longer branched alkanes (e.g., trimethyloctanes) were also susceptible to microbial attack. Although all ignitable liquids examined suffered at least to some extent from microbial degradation, gasoline, petroleum distillates, and oxygenates were the most susceptible. Isoparaffinic and naphthenic–paraffinic products were the most resistant to microbial degradation.  相似文献   

4.
Conventional Gas Chromatography‐Mass Spectrometry (GC‐MS) methods for the analysis of ignitable liquids (ILs) are usually time‐consuming, and the data produced are difficult to interpret. A fast IL screening method using direct analysis in real time mass spectrometry (DART‐MS) is proposed in this study. GC‐MS, QuickStrip DART‐MS, and thermal desorption DART‐MS methods were used to analyze neat ILs and thermal desorption DART‐MS without extraction was used to analyze ILs on five substrates (e.g., carpet, wood, cloth, sand, and paper). Compared to GC‐MS, DART‐MS methods generated different spectral profiles for neat ILs with more peaks in the higher mass range and also provided better detection of less volatile compounds. ILs on substrates were successfully classified (98 ± 1%) using partial least squares discriminant analysis (PLS‐DA) models based on thermal desorption DART‐MS data. This study shows that DART‐MS has great potential for the high‐throughput screening of ILs on substrates.  相似文献   

5.
Anticoagulant rodenticides are widely used for rodent control around the world. A rapid and sensitive method was developed and validated for the simultaneous determination of 13 anticoagulant rodenticides (coumafuryl, pindone, valone, warfarin, coumatetralyl, coumachlor, diphacinone, dicumarol, chlorophacinone, bromadiolone, difenacoum, flocoumafen, and brodifacoum) in human blood by liquid chromatography–tandem mass spectrometry. After liquid–liquid extraction, the anticoagulant rodenticides were separated on an Eclipse Plus C18 column. Linearities were observed for each analyte in blood ranging from 0.5 to 50 ng/mL, with correlation coefficients over 0.99. The limits of detection ranged from 0.01 to 0.2 ng/mL, and the limits of quantification were 0.5 ng/mL for all analytes. The intraday and interday precisions were <15%, and accuracies ranged from 80.3% to 111.0%. This validated method with high sensitivity has been applied in three anticoagulant rodenticide poisoning cases and has been used successfully in monitoring blood concentrations for months.  相似文献   

6.
Studying links between triacetone triperoxide (TATP) samples from crime scenes and suspects can assist in criminal investigations. Isotope ratio mass spectrometry (IRMS) and gas chromatography (GC)‐IRMS were used to measure the isotopic compositions of TATP and its precursors acetone and hydrogen peroxide. In total, 31 TATP samples were synthesized with different raw material combinations and reaction conditions. For carbon, a good differentiation and a linear relationship were observed for acetone–TATP combinations. The extent of negative (δ13C) fractionation depended on the reaction yield. Limited enrichment was observed for the hydrogen isotope (δ2H) values of the TATP samples probably due to a constant exchange of hydrogen atoms in aqueous solution. For oxygen (δ18O), the small isotopic range and excess of water in hydrogen peroxide resulted in poor differentiation. GC‐IRMS and IRMS data were comparable except for one TATP sample prepared with high acid concentration demonstrating the potential of compound‐specific isotope analysis. Carbon IRMS has practical use in forensic TATP investigations.  相似文献   

7.
Alignment of fire debris data from GC‐MS for chemometric analysis is challenged by highly variable, uncontrolled sample and matrix composition. The total ion spectrum (TIS) obviates the need for alignment but loses all separation information. We introduce the segmented total ion spectrum (STIS), which retains the advantages of TIS while retaining some retention information. We compare the performance of STIS with TIS for the classification of casework fire debris samples. TIS and STIS achieve good model prediction accuracies of 96% and 98%, respectively. Baseline removal improved model prediction accuracies for both TIS and STIS to 97% and 99%, respectively. The importance of maintaining some chromatographic information to aid in deciphering the underlying chemistry of the results and reasons for false positive/negative results was also examined.  相似文献   

8.
The chemical analysis of fire debris represents a crucial part in fire investigations to determine the cause of a fire. A headspace solid‐phase microextraction (HS‐SPME) procedure for the detection of ignitable liquids in fire debris using a fiber coated with a mixture of three different sorbent materials (Divinylbenzene/Carboxen/Polydimethylsiloxane, DVB/CAR/PDMS) is described. Gasoline and diesel fuel were spiked upon a preburnt matrix (wood charcoal), extracted and concentrated with HS‐SPME and then analyzed with gas chromatography/mass spectrometry (GC/MS). The experimental conditions—extraction temperature, incubation and exposure time—were optimized. To assess the applicability of the method, fire debris samples were prepared in the smoke density chamber (SDC) and a controlled‐atmosphere cone calorimeter. The developed methods were successfully applied to burnt particleboard and carpet samples. The results demonstrate that the procedure that has been developed here is suitable for detecting these ignitable liquids in highly burnt debris.  相似文献   

9.
This study investigates the use of Scanning electron microscopy–energy‐dispersive X‐ray (SEM‐EDX) as a diagnostic tool for the determination of the osseous origin of samples subjected to different temperatures. Sheep (Ovis aries) ribs of two experimental groups (fleshed and defleshed) were burned at temperatures of between 100°C and 1100°C in 100°C increments and subsequently analyzed with the SEM‐EDX to determine the atomic percentage of present elements. Three‐factor ANOVA analysis showed that neither the exposure temperature, nor whether the burning occurred with or without soft tissue present had any significant influence on the bone's overall elemental makeup (> 0.05). The Ca/P ratio remained in the osseous typical range of between 1.6 and 2.58 in all analyzed samples. This demonstrates that even faced with high temperatures, the overall gross elemental content and atomic percentage of elements in bone remain stable, creating a unique “fingerprint” for osseous material, even after exposure to extreme conditions.  相似文献   

10.
Here, we present a method of extracting drug residues from fingerprints via Direct Analyte‐Probed Nanoextraction coupled to nanospray ionization–mass spectrometry (DAPNe‐NSI‐MS). This instrumental technique provides higher selectivity and lower detection limits over current methods, greatly reducing sample preparation, and does not compromise the integrity of latent fingerprints. This coupled to Raman microscopy is an advantageous supplement for location and identification of trace particles. DAPNe uses a nanomanipulator for extraction and differing microscopies for localization of chemicals of interest. A capillary tip with solvent of choice is placed in a nanopositioner. The surface to be analyzed is placed under a microscope, and a particle of interest is located. Using a pressure injector, the solvent is injected onto the surface where it dissolves the analyte, and then extracted back into the capillary tip. The solution is then directly analyzed via NSI‐MS. Analyses of caffeine, cocaine, crystal methamphetamine, and ecstasy have been performed successfully.  相似文献   

11.
Abstract: A significant amount of research has been conducted into the use of stable isotopes to assist in determining the origin of various materials. The research conducted in the forensic field shows the potential of isotope ratio mass spectrometry (IRMS) to provide a level of discrimination not achievable utilizing traditional forensic techniques. Despite the research there have been few, if any, publications addressing the validation and measurement uncertainty of the technique for forensic applications. This study, the first in a planned series, presents validation data for the measurement of bulk nitrogen isotope ratios in ammonium nitrate (AN) using the DELTAplusXP (Thermo Finnigan) IRMS instrument equipped with a ConFlo III interface and FlashEA? 1112 elemental analyzer (EA). Appropriate laboratory standards, analytical methods and correction calculations were developed and evaluated. A validation protocol was developed in line with the guidelines provided by the National Association of Testing Authorities, Australia (NATA). Performance characteristics including: accuracy, precision/repeatability, reproducibility/ruggedness, robustness, linear range, and measurement uncertainty were evaluated for the measurement of nitrogen isotope ratios in AN. AN (99.5%) and ammonium thiocyanate (99.99+%) were determined to be the most suitable laboratory standards and were calibrated against international standards (certified reference materials). All performance characteristics were within an acceptable range when potential uncertainties, including the manufacturer’s uncertainty of the technique and standards, were taken into account. The experiments described in this article could be used as a model for validation of other instruments for similar purposes. Later studies in this series will address the more general issue of demonstrating that the IRMS technique is scientifically sound and fit‐for‐purpose in the forensic explosives analysis field.  相似文献   

12.
The cis and trans isomers of 3‐methylfentanyl and its three analogs were chemically synthesized, and these compounds were characterized and differentiated by gas chromatography/mass spectrometry (GC/MS), liquid chromatography/mass spectrometry (LC/MS), and nuclear magnetic resonance (NMR) spectroscopy. The cis and trans isomers of the 3‐methylfentanyl analogs were completely separated by GC/MS. Although the high temperature of the GC injection port caused thermal degradation of β‐hydroxy‐3‐methylfentanyl, the degradation was completely suppressed by trimethylsilyl derivatization. The isomers were also well separated by LC/MS on an octadecylsilyl column with 10 mM ammonium acetate and methanol as the mobile phase. The proton NMR signals were split when the hydrochloride salts of the 3‐methylfentanyl analogs were dissolved in deuterated chloroform because stereoisomers were formed by the coordination of the hydrochloride proton to the nitrogen of the piperidine ring of the 3‐methylfentanyl analogs.  相似文献   

13.
Techniques of 2D–3D superimposition are widely used in cases of personal identification from video surveillance systems. However, the progressive improvement of 3D image acquisition technology will enable operators to perform also 3D–3D facial superimposition. This study aims at analyzing the possible applications of 3D–3D superimposition to personal identification, although from a theoretical point of view. Twenty subjects underwent a facial 3D scan by stereophotogrammetry twice at different time periods. Scans were superimposed two by two according to nine landmarks, and root‐mean‐square (RMS) value of point‐to‐point distances was calculated. When the two superimposed models belonged to the same individual, RMS value was 2.10 mm, while it was 4.47 mm in mismatches with a statistically significant difference (p < 0.0001). This experiment shows the potential of 3D–3D superimposition: Further studies are needed to ascertain technical limits which may occur in practice and to improve methods useful in the forensic practice.  相似文献   

14.
The estimation of an individual's age at death plays a critical role in the investigation of unidentified human remains. The Suchey–Brooks method, which involves the analysis of degenerative morphological changes in the pubic symphysis, is currently widely used to estimate age in adults. This study tested the applicability of the Suchey–Brooks method on a contemporary adult Australian (Victorian) subpopulation by observing three‐dimensional volume‐rendered postmortem computed tomographic (PMCT) reconstructions of the pubic symphysis of 204 individuals aged 15–100 years. Results showed the method was reliable for females (85% correct allocations) but not for males (67% correct allocations). It is therefore recommended that extreme caution be used when applying the Suchey–Brooks method for estimating age at death of an individual in this subpopulation from PMCT images. The results suggest further investigation into alternate age estimation methods is required.  相似文献   

15.
Gunshot residues, produced after shooting activity, have acquired their importance in analysis due to the notoriety of firearms‐related crimes. In this study, solid‐phase microextraction was performed to extract the headspace composition of spent cartridges using 85‐μm polyacrylate fiber at 66°C for 21 min. Organic compounds, that is, naphthalene, 2,6‐dinitrotoluene, 2,4‐dinitrotoluene, diphenylamine, and dibutyl phthalate were detected and analyzed by gas chromatography‐flame ionization detection technique. Evaluation of chromatograms for diphenylamine, dibutyl phthalate, and naphthalene indicates the period after a gunshot was discharged, whether it was 1 days, 2–4 days, <5 days, 10 days, 20 days, or more than 30 days ago. This study revealed the potential effects of environmental factors such as occasional wind blow and direct sunlight on the estimation of time after spent cartridges were discharged. In conclusion, we proposed reliable alternative in analyzing the headspace composition of spent cartridges in a simulated crime scene.  相似文献   

16.
Chrome Yellow (PbCrO4·xPbSO4) was a common pigment in U.S. automobile OEM finishes for more than three decades, but in the early 1990s its use was discontinued. One of its main replacements was Bismuth Vanadate (BiVO4·nBi2MoO6, = 0–2), which was commercially introduced in 1985, as this inorganic pigment also produces a very bright hue and has excellent outdoor durability. This paper describes the in situ identification of Bismuth Vanadate in automotive finishes using FT‐IR and dispersive Raman spectroscopy and XRF spectrometry. Some differentiation of commercial formulations of this pigment is possible based on far‐infrared absorptions, Raman data, and elemental analysis. The spectral differences arise from the presence or absence of molybdenum, the use of two crystal polymorphs of BiVO4, and differences in pigment stabilizers. Bismuth Vanadate is usually not used alone, and it is typically found with Isoindoline Yellow, hydrous ferric oxide, rutile, Isoindolinone Yellow 3R, or various combinations of these.  相似文献   

17.
As the result of the communist terror in Poland, during years 1944–1956 more than 50,000 people died. Their bodies were buried secretly, and most places are still unknown. The research presents the results of identification of people buried in one of many mass graves, which were found at the cemetery Pow?zki Military in Warsaw, Poland. Exhumation revealed the remains of eight people, among which seven were identified genetically. Well‐preserved molars were used for the study. Reference material was collected from the closest living relatives. In one case, an exhumation of victim's parents had to be performed. DNA from swabs was extracted with a PrepFiler® BTA Forensic DNA Extraction Kit and organic method. Autosomal, Y‐STR amplification, and mtDNA sequencing were performed. The biostatistical calculations resulted in LR values from 1608 to 928 × 1018. So far, remains of more than 50 victims were identified.  相似文献   

18.
Bismuth oxychloride (BiOCl) was the first viable synthetic pearl pigment developed 50 years ago. It was only used for a limited time period in automotive paint (model years 1998–2000), serving to produce luster for a single Chrysler black metallic color. Identification of this pigment in an unknown automotive paint can thus facilitate determination of the vehicle of origin. Bismuth oxychloride imparts effects similar to those produced by silver/white mica pearlescent pigments, and such a pigment was used together with bismuth oxychloride in at least one original equipment manufacturer (OEM) basecoat. Silver/white micas are now used primarily in white pearl tricoat systems. This article describes the identification of bismuth oxychloride and silver/white mica pearlescent pigments in automotive finishes using FT‐IR spectroscopy, X‐ray fluorescence (XRF) spectrometry, and SEM/EDS analysis. Data for some cadmium pigments, which were used in automotive paint several decades ago, are also presented as they produce infrared absorptions similar to that of bismuth oxychloride.  相似文献   

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