共查询到20条相似文献,搜索用时 375 毫秒
1.
Cayli J. Meizel-Lambert M.A. John J. Schultz Ph.D. Michael E. Sigman Ph.D. 《Journal of forensic sciences》2015,60(6):1534-1541
Identification of osseous materials is generally established on gross anatomical features. However, highly fragmented or taphonomically altered materials may be problematic and may require chemical analysis. This research was designed to assess the use of scanning electron microscopy–energy-dispersive X-ray spectrometry (SEM/EDX), elemental analysis, and multivariate statistical analysis (principal component analysis) for discrimination of osseous and nonosseous materials of similar chemical composition. Sixty samples consisting of osseous (human and nonhuman bone and dental) and non-osseous samples were assessed. After outliers were removed a high overall correct classification of 97.97% was achieved, with 99.86% correct classification for osseous materials. In addition, a blind study was conducted using 20 samples to assess the applicability for using this method to classify unknown materials. All of the blind study samples were correctly classified resulting in 100% correct classification, further demonstrating the efficiency of SEM/EDX and statistical analysis for differentiation of osseous and nonosseous materials. 相似文献
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Quantitative analysis of tropane alkaloids in biological materials by gas chromatography-mass spectrometry 总被引:2,自引:0,他引:2
Namera A Yashiki M Hirose Y Yamaji S Tani T Kojima T 《Forensic science international》2002,130(1):34-43
A simple and rapid method for quantitation of tropane alkaloids in biological materials has been developed using an Extrelut column with gas chromatography-mass spectrometry (GC-MS). Biological materials (serum and urine) were mixed with a borate buffer and then applied to an Extrelut column. The adsorbed tropane alkaloids were eluted with dichloromethane before a GC-MS analysis. Atropine-d(3) was used as an internal standard. The extracted tropane alkaloids were converted to trimethylsilyl derivatives prior to GC analysis, to improve the instability of tropane alkaloids from heating and the property of them for a GC column. The recoveries of the compounds, which had been spiked to biological materials, were more than 80%. The GC separation of the derivatives from endogenous impurities was generally satisfactory with the use of a semi-polar capillary column. Tropane alkaloids showed excellent linearity in the range of 10-5000 ng/ml and the limit of detection was 5.0 ng/ml for biological materials. The present method is simple and more rapid than those previously reported, and was applied to a poisoning case. It is useful for the routine analysis of tropane alkaloids in cases of suspected tropane alkaloids poisoning. 相似文献
3.
Armitage S Saywell S Roux C Lennard C Greenwood P 《Journal of forensic sciences》2001,46(5):1043-1052
Laser micropyrolysis gas chromatography-mass spectrometry is used for the analysis of paint, photocopier toner, and synthetic fiber materials to test the forensic potential of this emerging technology. It uses a laser microprobe to selectively target very small parts of the materials for GC-MS analysis. Whereas the paint and the toner samples were amenable to direct laser pyrolysis, the synthetic fibers proved transparent to the 1064 nm laser radiation. The difficulty with the fibers demonstrates that a specific laser wavelength may not be appropriate for all types of materials. Nevertheless, the fibers were able to be indirectly pyrolyzed by impregnation in a strongly absorbing graphite matrix. A vast array of hydrocarbon pyrolysates was detected from the different materials studied. Unique product distributions were detected from each sample and in sufficient detail to facilitate individual molecular characterization (i.e., molecular fingerprinting). The integrity of the laser data were confirmed by comparison to data obtained from the same samples by the more conventional pyroprobe pyrolysis GC-MS method. The high spatial resolution and selectivity of the laser method may be advantageous for specific forensic applications, however, further work may be required to improve the reproducibility of the data. 相似文献
4.
Forensic anthropological examinations typically involve the analysis of human skeletal remains, but in cases where samples are very small and/or physically compromised, it may first be necessary to determine whether the material is even osseous or dental in origin. X-ray fluorescence spectrometry (XRF) is a technique that reveals the elemental composition of materials and is hypothesized to have utility in such cases. XRF analysis was conducted on a variety of tissues and materials in unaltered and altered (damaged) states. With few exceptions, osseous and dental tissues in unaltered and altered conditions contained characteristic levels of calcium and phosphorus, while other materials did not. Materials could be accurately identified as osseous or dental in origin based on the calcium and phosphorus levels identified by XRF, and we therefore conclude that XRF analysis is a valid and effective means of determining osseous or dental origin of unknown material. 相似文献
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Aziz N Greenwood PF Grice K John Watling R van Bronswijk W 《Journal of forensic sciences》2008,53(5):1130-1137
Pressure-sensitive adhesive tapes often represent key evidence of crimes such as assault, rape or homicide; thus, the development of analytical techniques able to contribute to a detailed characterization of these materials is of forensic importance. The gas chromatography-mass spectrometry (GCMS) analysis of the solvent extractable fractions of a suite of electrical and gaffer adhesive tapes spanning a range of colors and manufacturers identified a number of petroleum-derived hydrocarbons. Molecular and isotopic analyses of hydrocarbon constituents of complex materials have found wide analytical utility including the forensic investigation of oil spills and arson. Here, we investigate the utility of these techniques for characterizing the hydrocarbon composition of pressure-sensitive adhesive tapes for forensic correlation purposes. Subtle distinction of tape samples was evident in the GCMS distribution of several hydrocarbon groups including alkyl-naphthalenes, hopane and sterane biomarkers. Linear discriminant analysis of the abundances of these products provided high level differentiation of tape manufacturer. The distinction of different adhesive tape samples was further extended by measurement of their stable carbon isotopic values. The molecular and isotopic differences of the petroleum content of tapes are consistent with the use of different petroleum materials used in the manufacturing process and demonstrate the benefits of the combined use of complementary oil hydrocarbon characterization approaches. This study reveals the forensic potential of using established petroleum characterization methods for characterizing materials with a petroleum-derived hydrocarbon element. 相似文献
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Pigolkin IuI Murzova TV Zharov VV Zaĭtsev VV Mirzoev KhM 《Sudebno-meditsinskaia ekspertiza》2012,55(2):25-27
The analysis of the unfavourable outcomes of dental care based on the materials of forensic medical examinations carried out by the Bureau of Forensic Medical Expertise, Moscow Department of Health. 相似文献
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H Tsoukali-Papadopoulou 《Forensic science international》1987,34(1-2):63-65
The toxicological analysis of post-mortem materials often help determine the cause of death. When tissues have been fixed in formalin it may be possible to extract several drugs from the tissue and/or the preserving fluid. An unusual case of multiple poisoning is discussed from the aspect of laboratory analysis. 相似文献
10.
《Forensic science international》1996,79(2):69-81
The major metabolite of hydroxylated benzodiazepines is the β-glucuronide metabolite, thus a hydrolysis step is included in benzodiazepine analyses in urine. We evaluated the new Alltech (R,S) oxazepam and lorazepam β-glucuronide primary reference materials as hydrolysis controls and for use in proficiency testing. Using HPLC analysis and GC/MS analysis following acid and β-glucuronidase hydrolysis, we found that the lorazepam β-glucuronide material was >95% pure, but the oxazepam β-glucuronide material was only 54.0% pure. Recovery after hydrolysis with β-glucuronidase at 60 °C for two hours and 22 °C for 24 h was compared. There was no difference in the recovery of either drug incubated under both conditions. Using HPLC analysis to separate the R and S isomers of the glucuronides, we found that the S isomer hydrolyzes faster than the R isomer, but at optimal conditions hydrolysis of both isomers is complete. Alltech's glucuronide materials can be valuable as hydrolysis controls in method development and routine benzodiazepine analyses, but each laboratory must validate the purity of the materials and determine the acceptable references ranges for in-house controls made from these materials. The reference materials were also evaluated for possible use as quality control material for urine drug screening. The material had to be added at 130% of the reported cutoff concentration to produce a positive result on the Triage™ Panel for Drugs of Abuse. For the Triage™ Plus TCA Panel for Drugs of Abuse lorazepam β-glucuronide was added at 154% of the cutoff concentration, but addition of the oxazepam β-glucuronide at >200% of the reported cutoff concentration did not produce a positive result. Discrepancies may be due to preferential binding of antibodies to the S isomer, because the Alltech glucuronide materials do not contain the isomers in the same ratio as that excreted in human urine. 相似文献
11.
Circumstances of criminal activities involving radioactive materials may mean fiber evidence recovered from a crime scene could have been exposed to materials emitting ionizing radiation. The consequences of radiation exposed fibers on the result of the forensic analysis and interpretation is explored. The effect of exposure to 1-1000 kGy radiation doses in natural and synthetic fibers was noticeable using comparative forensic examination methods, such as optical microscopy, microspectrophotometry, and thin-layer chromatography. Fourier transform infrared spectroscopy analysis showed no signs of radiation-induced chemical changes in any of the fiber structures. The outcome of the comparative methods highlights the risk of "false negatives" associated in comparing colors of recovered fibers that may have been exposed to unknown radiation doses. Consideration of such results supports the requirement to know the context, including the environmental conditions, as much as possible before undertaking a forensic fiber examination. 相似文献
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Lee CL Coyle HM Carita E Ladd C Yang NC Palmbach TM Hsu IC Lee HC 《The American journal of forensic medicine and pathology》2006,27(2):121-125
Examination of stomach contents is one of the important steps in medical legal autopsy. Vegetative materials such as stems, roots, and seeds in stomach contents can be valuable evidence for providing investigative leads in death investigation. Currently, the identification of plant materials relies on microscopic and morphologic examination. We have found that many seeds are often protected from acid degradation during stomach digestion by their tough exterior seed coat. Tomato seeds were selected as a model system to assess DNA analysis and plant variety marker identification. The DNA-amplified fragment length polymorphism method was performed to determine if the DNA obtained from single seeds could be used for PCR analysis. From the amplified fragment length polymorphism results, some candidate markers for individualizing seeds from morphologically distinct tomatoes were identified. These data on DNA analysis of tomato seeds indicate amplified fragment length polymorphism is a viable procedure for the individualization of seeds from stomach contents in forensic investigations. 相似文献
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Andréasson H Nilsson M Budowle B Lundberg H Allen M 《Forensic science international》2006,164(1):56-64
Due to the different types and quality of forensic evidence materials, their DNA content can vary substantially, and particularly low quantities can impact the results in an identification analysis. In this study, the quantity of mitochondrial and nuclear DNA was determined in a variety of materials using a previously described real-time PCR method. DNA quantification in the roots and distal sections of plucked and shed head hairs revealed large variations in DNA content particularly between the root and the shaft of plucked hairs. Also large intra- and inter-individual variations were found among hairs. In addition, DNA content was estimated in samples collected from fingerprints and accessories. The quantification of DNA on various items also displayed large variations, with some materials containing large amounts of nuclear DNA while no detectable nuclear DNA and only limited amounts of mitochondrial DNA were seen in others. Using this sensitive real-time PCR quantification assay, a better understanding was obtained regarding DNA content and variation in commonly analysed forensic evidence materials and this may guide the forensic scientist as to the best molecular biology approach for analysing various forensic evidence materials. 相似文献
14.
Sub-sampling and preparing forensic samples for pollen analysis 总被引:1,自引:0,他引:1
Horrocks M 《Journal of forensic sciences》2004,49(5):1024-1027
The main forensic application of palynology is in providing associative evidence, assisting to prove or disprove a link between people and objects with places or with other people. Although identification and interpretation of pollen is a specialist job, sub-sampling and preparing pollen samples for analysis may be carried out by non-specialists. As few forensic laboratories have residing palynologists, laboratories may wish to reduce the cost of analysis or risk of contamination by doing their own sub-sampling and preparation. Presented is a practical guide for sub-sampling and preparing forensic samples for pollen analysis, providing a complete standard procedure for both the palynologist and non-specialist. Procedures for sub-sampling include a wide variety of materials commonly collected for forensic analysis (soil, clothing and other fabrics, footwear, twine and rope, firearms, granulated materials, plant and animal material, and illicit drugs), many of which palynologists will not be familiar with. Procedures for preparation of samples (pollen concentration) are presented as a detailed, step-by-step method. Minimizing the risks of laboratory and cross-sample contamination during sub-sampling and preparation is emphasized. 相似文献
15.
人线粒体DNA序列分析在法医学中的应用研究及其进展 总被引:1,自引:0,他引:1
综述人线粒体DNA(m tDNA)序列分析在法医学种属鉴别、个体识别,以及个体年龄推断中的应用研究及其进展,展望对m tDNA异质性的研究及建立人m tDNA数据库,并具有重要的法医学实践意义。 相似文献
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Contactless Visualization of Latent Fingerprints on Nonporous Curved Surfaces of Circular Cross Section—A Statistical Evaluation on the Materials as Plane Mirror 下载免费PDF全文
Wei Zeng Low B.Eng. Bee Ee Khoo Ph.D. Ahmad Fahmi Lim bin Abdullah Ph.D. 《Journal of forensic sciences》2018,63(4):1092-1098
A new contactless technique for latent fingerprint visualization on nonporous curved surfaces of circular cross section was introduced by Low et al. (1). The technique utilizes a plane mirror to convey the light rays toward the inspected surfaces for latent fingerprint visualization. This research activity came up as an extension of the previous study which utilized an aluminum plate as the plane mirror to illuminate the inspected surfaces. Dulling spray was used to increase the diffuse component of the reflective aluminum plate. However, the amount of dulling spray will affect the uniformity of the illumination on the inspected curved surfaces. In this study, a study on the new materials for the plane mirror was carried out. Coated aluminum, opal, and ground glass diffusers were selected as the new materials. The performance of the new materials was compared to the aluminum based on the quality of the captured images on various nonporous cylindrical surfaces. A statistical approach known as randomized complete block design was used to design the experiment. The quality of the captured images was obtained using Spectral Image Validation and Verification. Two‐way analysis of variance and Fisher's least significant difference test were used to analyze the quality of the images. From the results of the statistical analysis, coated aluminum has the best performance compared to aluminum, opal, and ground glass diffusers. 相似文献
18.
The ability to distinguish human cremains from filler materials can be important in a variety of situations, the most notorious recent example being the Tri-State Crematorium incident. However, the majority of the papers in the recent literature present methods that rely on trace or minor element analysis, usually followed by a statistical or variable cluster analysis, to determine attribution. This approach is inherently risky, as there is significant natural variation in the trace and minor element body burdens within the human population and no real baseline for comparison. Bones and teeth are a form of calcium phosphate that is part of the mineral group apatite, often referred to as bioapatite. X-ray diffraction (XRD) spectroscopy is a technique that is used to identify minerals by their crystalline structures rather than their elemental composition. The members of the mineral group apatite have a highly flexible hexagonal (6/m) structure that is able to incorporate small amounts of a wide variety of elements. However, its structure, and therefore its X-ray diffraction pattern, is distinct from the crystalline structures of all of the commonly reported filler materials, most of which are composed of some combination of Portland cement, limestone aggregate and quartz sand. XRD has several advantages over other analytical techniques for the identification of cremains. It is non-destructive, requires relatively small amounts of material, is unaffected by the elemental variations found in bioapatite, and can be used to semi-quantify the components of a mixture, thus determining the relative level of contamination of a sample. This paper presents the results of X-ray diffraction spectroscopy analysis of human cremains and a variety of common filler materials. 相似文献
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Critical Criminology - Through an analysis of interviews with Southern California attorneys, supplemented by archival materials, this article contributes to the literature on gangs, critical... 相似文献
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The clandestine manufacture of methamphetamine is a spreading epidemic. Manufacturing methods are constantly changing, necessitating the implementation of new analytical tools to identify materials from these labs. Characterization of phosphate, phosphite, and hypophosphite ions is necessary to distinguish the various phosphorus-iodine manufacturing methods that are popular methods for reducing pseudoephedrine to methamphetamine. This work describes a capillary electrophoresis method to separate acetate, azide, bromide, carbonate, chlorate, chloride, chromate, fluoride, hypophosphite, iodide, nitrate, nitrite, perchlorate, phosphate, phosphite, sulfate, sulfite, and thiocyanate. The CElixerOA 8.2 dynamic coating system was modified by lowering the capillary temperature to 15 degrees C and using an acid flush between runs to remove adsorbed materials. This allows detection of ions down to between 10 and 30 parts per million with percent relative standard deviations of normalized migration times under 0.1%. This method is a valuable tool for the characterization of phosphate, phosphite, and hypophosphite in routine analysis of clandestine methamphetamine manufacturing evidence and has a broader application in other areas of forensic analysis. 相似文献