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11.
Novel psychoactive substances (NPS) are synthetic drugs that pose serious public health and safety concerns. A multitude of NPS have been identified in the United States, often implicated in forensic investigations. The most common and effective manner for identifying NPS is by use of mass spectrometry and the true utility lies within nontargeted acquisition techniques. During this study, a liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QTOF-MS) assay was developed, validated, and implemented for forensic toxicology testing. A SCIEX TripleTOF™ 5600 + with SWATH® acquisition was used. Resulting data were compared against an extensive library database containing more than 800 compounds. The LC-QTOF-MS assay was applied to the reanalysis of biological sample extracts to discover emergent NPS. More than 3,000 sample extracts were analyzed, and more than 20 emerging NPS were detected for the first time. Among these were isopropyl-U-47700, 3,4-methylenedioxy-U-47700, fluorofuranylfentanyl, N-methyl norfentanyl, 2F-deschloroketamine, 3,4-methylenedioxy-alpha-PHP, eutylone, and N-ethyl hexedrone.  相似文献   
12.
In this study, the nondestructive differentiation of individual white polyester clothing fibers was accomplished via synchrotron radiation microbeam X-ray fluorescence (SR-μ-XRF) analysis. SR-μ-XRF with vertical focusing is a useful nondestructive method for the analysis of a single polyester clothing fiber. Kirkpatrick–Baez (KB) mirror was used to vertically focus 20 keV X-rays for the analysis of 22 individual white polyester fibers taken from clothing commonly sold in Japan. SR-μ-XRF with a vertical focused 2 μm (V) × 300 μm (H) beam was approximately 12.8 times more sensitive than SR-XRF with an unfocused 300 μm (V) × 300 μm (H) beam for the detection of elements in single fibers. The minimum detection limits (MDLs) of the SR-μ-XRF method were 8.15 ppm for Cl and 0.06 ppm for Br. In addition to Ti in TiO2 delustering agents, Zr and Nb impurities in the delustering agents were detected in individual fibers. Sb from a polymerization catalyst and Co from a transesterification catalyst were also detected in individual fibers. Comparing the Ti Kβ/Sb Lα,β and Zr Kα/Nb Kα X-ray intensity ratios was a useful way to distinguish individual clothing fibers, and 98% of the fibers were differentiated when additional trace elements were used as discrimination indicators.  相似文献   
13.
Gunshot residue (GSR) analysis and their interpretation provide crucial information on a criminal investigation involving the use of firearms. To date, several approaches have been proposed for the implementation of a combined sampling and analysis of inorganic (IGSR) and organic GSR (OGSR). However, it is not clear at this stage if concurrent analyses of both types of residue might be detrimental to the analysis of IGSR currently applied in forensic laboratories. Thus, this work aims to compare and evaluate three different protocols for the combined collection and analysis of IGSR and OGSR. These methods, respectively, involve the use of a modified stub (with two halves, one for the detection of IGSR and the other for the analysis of OGSR); the sequential recovery of GSR with two stubs mounted with different adhesives (double-sided carbon tape and Tesa® TACK) and the sequential analysis of IGSR and OGSR from a single carbon stub following carbon deposition. The detection of IGSR was carried out using SEM-EDX, while OGSR analysis was performed using ultra-high-performance liquid chromatography–tandem mass spectrometry (UHPLC-MS/MS). Obtained results for experiments performed using Geco Sinoxid® ammunition indicated that sequential analysis was the most suitable protocol for the combined collection and analysis of both IGSR and OGSR. A higher number of inorganic (characteristic and consistent) particles and higher concentrations of ethylcentralite, N-nitrosodiphenylamine, diphenylamine, and nitroglycerin were recovered with this method.  相似文献   
14.
目的 运用气相色谱-质谱联用法对不同方法提取的三七挥发性成分进行比较分析。方法 分别采用回流提取法、超声提取法、静态顶空法提取三七挥发油,运用气相色谱-质谱联用技术,运用NIST11.0质谱数据库和峰面积归一化法对已分离的化合物进行鉴定并计算各成分的相对含量。结果 从回流提取、超声提取、静态顶空法提取的三七挥发油中分别鉴定出60、50、24个挥发性成分。在静态顶空法中相对质量分数最高的是香桧烯,占挥发性成分的24.97%;在回流提取法和超声提取法中相对质量分数最高的都是聚炔类物质环氧十三烷-4,11-二炔,分别占挥发性成分的9.97%和14.75%。首次从三七挥发性成分中鉴定出3个聚炔类化合物和2个甾体类化合物。结论 三七中挥发性成分主要为烷烃类、烯烃类、醛类、酸类、酯类、萜类、聚炔类、甾体类和杂环类物质。3种方法的补充利用可较全面地提取出三七中的挥发性物质。  相似文献   
15.
New technology has expanded the opportunities for energy companies within the United States, often bringing them into populated communities and requiring them to negotiate deals with landowners. This case study focuses on how one group of landowners in northeastern Pennsylvania creatively reimagined the process of negotiating in a natural gas deal. They used collective bargaining for leverage, and the Internet and social media to level the informational playing field. These techniques allowed them to develop trust within the group and ultimately with one company, as they sought to protect their environment and enhance their financial gain.  相似文献   
16.
观察大鼠吸入原油蒸气和汽油蒸气对器官损害的组织形态学变化,可为法医学鉴定和医学的防治提供依据。健康成年SD大鼠25只,随机分为正常对照组、原油实验组、93号无铅汽油实验组、死后对照组,每组5只。建模成功后,在光镜下观察大鼠主要器官的组织形态学变化。动物模型的制作均获得成功,光镜下观察心脏、肺脏、肝脏、肾脏、脑组织细胞形态均有明显的异常改变。大鼠吸入原油蒸气和汽油蒸气对主要器官有明显的损害作用,为法医学鉴定提供了有价值的依据。  相似文献   
17.
A discrete nebulisation technique has been developed for the multi-element analysis of 100-μl solution droplets by inductively coupled plasma-optical emission spectrometry (ICP-OES). The technique increases analytical speed and uses very small solution volumes with only a slight degradation in detection limits when compared to continuous solution introduction.To evaluate its suitability in casework, small alloy fragments were produced by cutting with a hacksaw, sample division and filing. The analysis of fragments from two different brasses indicated that quantitative data could be obtained from fragments as small as 10 μg. The accurate determination of lead, a non-homogeneous constituent of leaded brasses, required sample sizes an order of magnitude greater. Analysis of an alloy of fine grain structure (copper-nickel) demonstrated that quantitative data could be obtained from samples weighing a few micrograms or less.  相似文献   
18.
This paper reviews the role of internal European Union (EU) policies and measures in implementing the target for greenhouse gas mitigation in the Kyoto Protocol. It starts with a discussion of the EU Burden Sharing Agreement, which distributes the target between Member States. This leads to a review of the appropriate level of implementation of policies, i.e. at the EU level or Member State level. There is a role for the flexible mechanisms of the Protocol, particularly emission permit trading, in complementing Member State policies at the EU level. The implementation is to be done against the background of three major factors which may have an important bearing on the policies: the probable long-term requirement of substantial reductions in greenhouse gas emissions a changing structure of energy markets, following liberalisation of the gas and electricity markets EU enlargement to include economies in transition with the potential for further substantial reductions in emissions.The paper concludes with a discussion of ancillary benefits of the policies that may be substantial and a summary of the position as regards the "unfinished business" of the Protocol to be discussed at the Conference of the Parties in the Hague in November 2000.  相似文献   
19.
目的建立高效液相色谱-质谱法测定人尿液中乙基葡萄糖醛酸苷。方法取空白人尿液加入EtG-D5内标工作液和冷甲醇(4℃),经涡旋、离心,取上清液于水浴氮气吹干,以沉淀杂质,采用Agilent Zorbax Bonus-RP色谱柱分离,以乙腈∶0.1%甲酸水溶液(5∶95)为流动相,采用负离子模式质谱检测,在选择离子监测模式下进行定性和定量测定。结果尿液中EtG在50~5 000ng/mL范围内线性关系良好,检出限为18ng/mL,方法回收率为90.2%~101.7%,相对标准偏差小于10%。结论所建方法简便,具有较高的回收率和精密度,适用于尿液中EtG的检测。  相似文献   
20.
Abstract: A new screening method for detecting gamma-hydroxybutyric acid (GHB) in drink matrices, using the IonSense, Inc. (Saugus, MA) direct analysis in real time (DART) ion source coupled to a JEOL exact mass time-of-flight mass spectrometer (AccuTOF), was validated and compared with the current screening methodology. The DART ion source allows for analysis of samples under ambient conditions with little to no sample preparation. Fifty drink specimens were spiked at levels of 1, 2, 3, and 4 mg/mL GHB, and analyzed on the AccuTOF-DART. Positive detection of GHB occurred for each of the samples at each concentration level, giving 100% accuracy for the samples tested. Twenty-five of the 50 drink specimens were spiked at 1 mg/mL GHB and tested using a color test known as the GHB Color Test #3. Only two of these 25 specimens tested positive for the presence of GHB, giving only 8% accuracy. Implementation of this new methodology as a screening tool for GHB analysis will quickly eliminate negative specimens allowing the examiner to focus analysis time on those that screened positive.  相似文献   
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