首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
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   

2.
Recently, tablets inscribed with the Mitsubishi 3-diamond logo, and sold as 3,4-methylenedioxymethamphetamine (MDMA), were found to contain p-methoxymethamphetamine (PMMA), a compound with MDMA-like effects. Shortly after this first submission, similarly inscribed tablets were encountered containing both PMMA and p-methoxyamphetamine (PMA). This second tablet composition has been implicated in several recent deaths in the US. Because two other positions are available for mono-methoxy substitution on the phenyl ring, it is essential that the correct identification be made for these compounds. Analytical data are supplied to enable differentiation of these ring isomers as well as the ketones that serve as their precursors.  相似文献   

3.
4-Methylmethamphetamine has been detected in samples submitted for analysis in several states throughout Australia. Six ring substituted methyl isomers of methamphetamine and amphetamine were synthesised and analysed. As the regioisomeric 2-, 3- and 4-methylmethamphetamine and 2-, 3- and 4-methylamphetamine have virtually identical mass spectra, the use of MS is an ineffective technique to discriminate between these closely related compounds. We set out to determine whether the regioisomers could be differentiated by a combination of GC-MS, acetyl derivatisation and GC-IRD. We demonstrate that the three isomers of methylmethamphetamine and methylamphetamine can be separated by GC, and a combination of acetyl derivatisation and vapour phase IR can identify the specific ring substituted compound.  相似文献   

4.
The sites, numbers and lengths of wounds of the skin of the scalp and head caused by blunt injuries (falls from standing position, falls downstairs, blows) in an autopsy series. Analysis of the localization, length and number of wounds located at the head in 305 autopsy cases of falls from a standing position (203 cases), falls downstairs (51 cases) and blows with relatively long materials (51 cases). For the distinction between falls and blows, among several other aspects the so-called rule of the hat-brim-line is described: in cases of falls from a standing position down to a flat bottom, contusions can be expected in or near a line which represents the greatest horizontal circumference of the skull, whereas in cases of blows the contusions lay above this area. Although such a tendency was found in our material, a rule could not be confirmed: only approximately 55% of the wound due to blows were above this line, and in cases of falls from a standing position ca. 1/3 of the wounds were above this area. Only in the (dorso-frontal and parietal) region "top of the head" contusions due to falls from a standing position were quite uncommon. The mean length and length distribution of wounds in the hat-brim-zone was not different between the 3 causes of injuries; in positions above this, wounds due to blows were longer compared to those by falls. In falls from a standing position, only exceptionally more than 1 wound was found, whereas in cases of homicide several or many wounds were common. Single wounds due to blows were only found in cases, in which the victims were knocked down but not killed by blunt forces, and death was caused by other methods (e.g. strangulation or stabbing).  相似文献   

5.
The ring substituted methyl isomers of methcathinone, 2-, 3- and 4-methylmethcathinone were analysed. The 2- and 3-isomers were synthesized. The 4-methylmethcathinone isomer is also known as mephedrone and has been widely studied. We present GCMS, NMR and IR data for the three isomers. We show that the three isomers can be separated by GCMS and that the IR spectra for the three compounds can be used to distinguish between them. A seized sample was analysed and it was found to contain 4-methylmethcathinone and benzocaine.  相似文献   

6.
The electron ionization (EI) of aromatic ring-substituted isomers gives virtual identical mass spectra which seriously affects their analysis. Especially regioisomeric meta- and para-ring-substituted compounds cannot show any ortho-effect reactions making their differentiation by mass spectrometry impossible. Furthermore o-, m- and p-substituted compounds can only be separated insufficiently by chromatography due to their very similar retention that do not allow univocal identification. Product ion mass spectrometry has proved to be a useful tool to differentiate structurally closely related fluorophenethylamines even in the case of the meta- and para-isomers. A series of N-alkylated o-, m- and p-fluoroamphetamines and 1-(4-fluorophenyl)butan-2-amines have been synthesized in microscale and studied by product ion spectrometry. The combination of chemical ionization (CI) and product ion spectrometry of hydrogen fluoride loss ions [M+H?HF]+ allows a univocal differentiation of all studied fluoro-substituted phenethylamines without prior derivatization. This method with submicrogram detection limits provides great advantages for the differentiation between aromatic regioisomeric fluorophenethylamine designer drugs where other methods such as nuclear magnetic resonance (NMR) spectrometry lack sufficient sensitivity or might fail because complex mixtures have to be analyzed.  相似文献   

7.
《Federal register》1982,47(111):25026-25029
This document contains proposed regulations relating to the determination of the amount of proceeds of issues of industrial development bonds sold by the issuer at a substantial discount. This amount is used in determining whether "substantially all" of the bond proceeds are used for an "exempt purpose", i.e. those described in section 103(b) (4), (5), (6), or (7) of the Internal Revenue Code, and for purposes of the "major portion" test in section 103(b)(2). The regulations would affect issuers, holders, and recipients of the proceeds of industrial development bonds of the type described above.  相似文献   

8.
This study presents and discusses the mass spectrometric, nuclear magnetic resonance spectroscopic and infrared spectroscopic data of the designer drugs pentedrone (2-methylamino-1-phenylpentan-1-one) and its methylenedioxy analog pentylone (2-methylamino-1-(3,4-methylenedioxyphenyl)pentan-1-one). The structure elucidation of the aliphatic parts was carried out by product ion spectroscopy of the immonium ion with m/z=86 formed after electron ionization, and by one- and two-dimensional (1)H- and (13)C-NMR spectroscopy on the hydrochloride salts to verify the structure of the alkyl side chain and to determine the methylenedioxy position in the aromatic ring of pentylone. Furthermore, two typical cathinone synthesis by-products were detected besides the main compounds. Their mass spectra are discussed and for one of them (1-methylamino-1-phenylpentan-2-one (isopentedrone)) a NMR assignment was possible in the existing mixture.  相似文献   

9.
目的建立了鸦片中吗啡、可待因、蒂巴因、罂粟碱、那可汀5种常量生物碱和牛心果碱、劳丹宁、劳丹素等12种痕量生物碱同时分离鉴定的超高效液相色谱-高分辨四极杆飞行时间串联质谱(UPLC/Q-TOF)方法。方法采用Agilent Eclipse Plus C18RRHD(2.1 mm×100 mm,1.8μm)色谱柱,以10 mM甲酸铵溶液和乙腈体系梯度洗脱,使用ESI离子源,正离子模式下采集数据。结果借助UPLC的快速分离和Q-TOF-MS测定的精确分子量和二级碎片信息,实现了17种生物碱的检测。应用SIMCA-P软件对78份国产鸦片和200份缅甸产鸦片进行偏最小二乘法判别分析(partial least squaresdiscriminate analysis,PLS-DA),比较不同地区鸦片样品中生物碱的差异,建立了区分国产鸦片和缅甸产鸦片的判别方法。结论所建立的方法用于鸦片样品中常量和痕量生物碱的检测及鸦片样品的产地判别,具有快速、高效、灵敏、准确的特点。  相似文献   

10.
Recent years have seen a wide discussion of populism in penal policy, which is internationally regarded as a strong drive for establishing punitive tendencies. Generally, “penal populism” is characterized by an extensive consensus across the most influential political parties, a punitive orientation, and the dismissal of scientific or professional expertise. Recent penal policy therefore appears to be a relatively unified practice strongly oriented toward punitive measures that primarily address the public and its perceived need for protection. Because analyses of Anglophone countries are predominant in this discussion, we contrast them with a reconstruction of debates on youth crime in German parliaments from 1970 to 2012. They exhibit a wide variety of populist articulations. Although they imply a strong punitive bias, they also encompass a very heterogeneous rhetoric of penal policy. In conclusion, we argue that penal populism can (and should) be described as a tactical practice, i.e., as political maneuvering employed to negotiate the prospects of punitive and other styles of politics.  相似文献   

11.
Abstract:  Estimation of living stature has obvious utility in the identification process. Typically, anthropologists estimate stature from the measurement of long bone length. This type of analysis is traditionally conducted on skeletonized or badly decomposed remains, so collection of the necessary bone measurements is relatively simple. As the role of anthropologists expands into medical examiner offices and mass fatality incidents, the analysis of fleshed bodies and body parts is a more common scenario. For stature estimation in these types of cases (e.g., analysis of body portions recovered from an aircraft crash site or from intentional dismemberment), the presence of soft tissue on the human remains would usually necessitate dissection to expose skeletal elements to derive metric data for stature estimation. In order to circumvent this step, this paper provides various formulae that allow for standard anthropometric (i.e., soft tissue) measurements to be used in place of skeletal measurements. Data were compiled from several anthropometric studies (National Health and Nutrition Examination Survey [NHANES] and U.S. Army Anthropometric Survey [ANSUR]) and numerous regression models are presented. Results are compared between skeletal measurements and the anthropometric measurements from each study. It was found that the ANSUR models are similar to the skeletal models, while the NHANES models exhibit weaker correlation coefficients and higher standard errors. Overall, this study finds that stature estimates derived from anthropometric data provide good results and remove the necessity for dissection when working with fleshed body portions.  相似文献   

12.
Vegetable oils have the ability to spontaneously heat under certain conditions, which may lead to spontaneous ignition. While the oils are not often encountered in forensic casework, they may be suspected in some fire cases. As these oils are not effectively analyzed using traditional fire debris analysis methods, a protocol must be established for extracting vegetable oils from fire debris. In this study, a protocol was developed for the extraction, derivatization, and analysis of vegetable oils from fire debris. Three derivatization methods were compared to establish an optimal derivatization procedure to convert the fatty acids found in vegetable oils to the fatty acid methyl esters (FAMEs) used in analysis. Three different gas chromatograph columns and programs were examined to determine which was best suited for the separation and analysis of FAMEs. The procedure was tested and refined using a variety of neat and burned vegetable oils, in addition to extractions from oils burned on commonly encountered fire debris materials. The findings of this research will serve as a starting point for further understanding and research of vegetable oils in fire debris.  相似文献   

13.
Stretchmark-like tears of the inguinal region are commonly referred to as typical lesions in pedestrian accidents when the victim is run over by a motorcar. These lesions can also be observed when a pedestrian is hit by a vehicle while being in an upright position. Stretchmark-like tears are due to hyperextension or excessive abduction of the hip joint. Characteristic morphological features are variable numbers of equally superficial and parallel tears of the skin following the skin's cleavage lines. Drivers of two-wheeled vehicles may exhibit inguinal stretchmark-like tears when they hit an obstacle with their bent knee, suffering excessive abduction of the hip joint. Finally, stretchmark-like tears are described in victims of collisions with railed vehicles, of aircraft crashes and--very rarely--in severely injured car passengers.  相似文献   

14.
Do term limits impede the ability of legislators to effectively set fiscal policy? To address this question, I examine state bond ratings from 1996 to 2009. Bond ratings serve as a valuable indicator of a state's fiscal performance, gauging the risk and uncertainty that investors face when buying these bonds. In addition, bond ratings are important policy ends in themselves. High bond ratings make it easier for states to borrow and raise revenue, while lowering interest rates. Results from analyses of “Term‐Limitedness” and legislator experience suggest that term limits negatively impact a state's fiscal performance, leading to lower bond ratings.  相似文献   

15.
The purpose of this article is to explore how the features of districts affect representation activities in the Chilean Congress. Based on an analysis of interventions by deputies in the so-called Incidents Hour (Hora de Incidentes), we argue that district conditions affect the kind of appeals that deputies make. Specifically, we test two main hypotheses: a) that the degree of rurality of districts predicts greater use of policy intervention at the local level (local credit claiming), and b) that distance from the centre is an incentive for deputies to taking a position on local issues (local position taking). This article contributes to an understanding of how institutional spaces in the Congress serve not only as instruments for legislation but also, and with equal relevance, for representing constituents at the district level.  相似文献   

16.
This paper examines a relatively new trend: market‐based crime prevention. The insurance firm is an exemplary agent of this new type of crime prevention. Although the traditional focus of insurance has been on losses sustained after a crime or other catastrophe, we explore the shift from reactive to proactive crime management by the insurance industry. This trend is part of a more general decentralization of policing, from state‐controlled agents to community‐ and market‐based third parties. New ideologies support these shifts, including an actuarial logic about crime and a view of the prudent person.  相似文献   

17.
Psilocin (4-hydroxy-N,N-dimethyltryptamine, 4-HO-DMT) and bufotenine (5-hydroxy-N,N-dimethyltryptamine, 5-HO-DMT), which are both naturally occurring compounds, are classified as controlled substances in numerous countries due to their pharmacological activities and recreational usage. There are two other benzene ring regioisomers, 6-hydroxy-N,N-dimethyltryptamine (6-HO-DMT) and 7-hydroxy-N,N-dimethyltryptamine (7-HO-DMT), which are not classified by name as controlled substances, and which were synthesized for this current work. The four isomers were analyzed using routine methodologies employed by the Israel's Police Division of Identification and Forensic Science (DIFS) Laboratory, namely thin layer chromatography (TLC), Fourier transform infrared spectroscopy (FTIR), and gas chromatography mass spectroscopy (GC-MS). It was found possible to differentiate the four isomers. Forensic specimens that were suspected to be psilocybe mushrooms were examined, confirming that it is now possible to unequivocally identify the presence of psilocin and rule out the presence of its other isomers.  相似文献   

18.
All the commonly used non-steriodal anti-inflammatory drugs (NSAIDs), except mefenamic acid, when extracted from the pharmaceutical dosage forms or the urines of users, and derivatized by silylation and then analysed by GC/MS, gave the mono- or the di-trimethylsilyl derivatives (depending on the number of derivatized groups in the drug) as the sole products. Mefenamic acid gave a mixture of products. When extracted from pharmaceutical dosage froms or from the urines of users, and analysed by GC/MS without derivatization, some of the NSAIDs were separated and detected as the unchanged molecules as the sole products, while others were separated and detected in altered forms as sole products or mixtures, depending on: (a) the solvent in which the extract was dissolved for injection into GC/MS, (b) the chemical structure of the drug, and (c) specifically for diflunisal, the presence or absence of potential methylating and/or acetylating agents on the GC column and/or septum. The main thermally-induced reactions of the underivatized NSAIDs included (i) methyl ester formation at the COOH group when the extract was dissolved in methanol, (ii) decarboxylation (i.e., loss of CO2), (iii) dehydration (i.e., loss of H2O) when the chemical structure permitted, such as for diclofenac, and (iv) cleavage at a carbon-heterocyclic nitrogen bond when one is present in an NSAID. Heating the urine in approximately 2 M HCl at 100 degrees C for 30 min, has been found to be a satisfactory means for effecting hydrolysis of the NSAIDs glucuronide conjugates. No metabolites, resulting from aromatic-ring hydroxylation, have been detected in urine for any of the NSAIDs studied.  相似文献   

19.
栾珊 《行政与法》2007,(9):16-18
后农业税时代给农村基层政府的定位是"服务型政府"。乡镇政府要尽快走出现阶段面临的一系列困境,必须理顺纵横关系,构建科学合理的分权体制;细分公共产品,构建互动合作的供给机制;激活民间力量,实现乡村治理的模式转换,才能最终实现从"自利性"向公益性的转型。  相似文献   

20.
The Inventory of Problems-29 (IOP-29; Viglione, Giromini, & Landis, Journal of Personality Assessment, 99(5), 534–544, 2017) is a 29-item, recently published, self-administered test aimed at assessing the credibility of various symptom presentations. Although available research strongly supports the use of this symptom validity test in malingering-related contexts, to date, only few studies have analyzed data from real-life forensic evaluations. To fill this gap and explore ecological and convergent validity, the current study analyzed data from 74 court-ordered evaluations aimed at establishing the possible presence of psychological injury. Such evaluations are high-stakes situations in which exaggeration or malingering occur relatively often. We used a research-supported and popular symptom validity test, i.e., the Structured Inventory of Malingered Symptomatology (SIMS; Smith & Burger, Journal of the American Academy on Psychiatry and Law, 25:180–183, 1997), as our criterion variable. The IOP-29 produced excellent area under the curve (AUC) values of .98 with a recommended SIMS total score cutoff (≥ 17) and .99 when eliminating too-close-to-classify cases (Rogers & Bender, 2018) and very large Cohen’s d effect sizes of 2.98 and 3.59, respectively. Crucially, when implementing established cut scores from previous research, the IOP-29 yielded very high specificity and sensitivity rates, and the predictions from the two tests were strikingly similar. Taken together, these findings support the strong convergent validity of the IOP-29 and its utility in applied clinical and forensic settings.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号