Application of three spectrometric methods to total selenium determination in postmortem material in a case of acute selenium compound poisoning

Three spectrometric methods, that is, spectrofluorimetry (SF), atomic absorption spectrometry with electrothermal atomization (ET-AAS), and atomic fluorescence spectrometry with hydride generation (HG-AFS) were used for the determination of total selenium in biological samples taken from postmortem material in a case of acute selenium compound poisoning. The precision of the SF, ET-AAS, and HG-AFS methods (RSD, n=10) was found to be in the ranges of 10.0-15.0, 3.0-6.0 and 1.0-1.5%, respectively, and the detection limit was 10.0, 4.0, and 0.1 μg/L of Se, respectively. In the case of HG-AFS, the analytical procedure takes less time and is less laborious than the other methods considered. The obtained results show the usefulness of the HG-AFS method as a supplementary analytical tool to the SF and ET-AAS methods with respect to the determination of selenium as well as the possibility of using this method as a primary one in forensic toxicology practice.     

Discriminating Hodgdon Pyrodex® and Triple Seven® Using Gas Chromatography–Mass Spectrometry

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.     

甲基苯丙胺和乙醇在染毒大鼠体内联用的实验研究

目的研究甲基苯丙胺（MA）和乙醇联合应用在急性、亚急性染毒大鼠体内的情况。方法以MA1.0 mg/kg剂量对慢性自由饮酒大鼠多次腹腔注射,分别建立急性、亚急性染毒大鼠模型;处死后即时检测血中乙醇浓度、体液和组织样品中MA的浓度。结果多次注入MA药后,亚急性中毒大鼠体内的MA浓度高于急性中毒大鼠;急性和亚急性联合中毒大鼠体内MA浓度均高于急性和亚急性单一药物组。结论无论是否联用乙醇,14d内增加注射次数会在大鼠体内产生不同程度的MA残留;与乙醇联用可加速MA在大鼠体内的吸收,其药物浓度的升高程度随生物样品不同存在差异。     

海运温室气体减排国际法律制度研究

介绍国际海事组织制定国际海运温室气体减排法律制度的背景,分析制定相关法律制度的可行性和形势,提出并探讨四个关键问题,即立法目的、共同但有区别责任原则的体现、法律文件的形式、是否构成海运服务贸易壁垒,揭示其背后深层次的政治、经济、技术和法律问题,指出国际海运温室气体减排法律制度将给船舶技术、国际海运贸易、航运经营与运营带来深远影响。     

超高效液相色谱-串联质谱法同时测定尿液中16种抗生素

目的 建立同时分析尿液中16种抗生素的超高效液相色谱-串联质谱(UPLC-MS、MS)方法.方法 以哌拉西林为内标.尿样中的目标化合物经Oasis HLB固相萃取柱富集、纯化,利用ZORBAX SB-C18色谱柱,以0.1%的甲酸溶液-乙腈为流动相经梯度洗脱分离,采用多反应监测(MRM)模式进行分析.结果各化合物的最低...     

气/质联用法检测鱼藤中鱼藤酮

目的建立气相色谱/质谱联用法检测鱼藤中鱼藤酮的方法。方法将鱼藤根净化处理后使用三氯甲烷浸提,提取液浓缩后经FINNIGAN POLARIS Q型GC/MS气质联用仪检测。结果通过质谱库匹配检出鱼藤酮。结论本方法操作简便、结果准确,易于推广应用,适用于鱼藤酮的检测。     

微波衍生化和GC/MS/MS技术分析血、尿中的吗啡

目的建立了血、尿等生物检材中海洛因代谢产物吗啡的定性分析方法。方法以丙酸酐为衍生化剂,采用微波衍生化技术结合GC/MS/MS进行分析。结果当CID电压为0.9V时,衍生化物的母离子与子离子碎片信息丰富,碎片为m/e268、324、342。结论此方法科学、准确,灵敏度高,能满足吸食海洛因类、吗啡类毒品人员的生物检材的检验要求。     

中国商业银行碳金融业务发展战略研究

当前碳金融已经成为全球商业银行竞争的新领域,中国商业银行拓展碳金融业务已是大势所趋。该文对中国发展碳金融的必要性和国内外商业银行在碳金融领域的发展现状进行了分析,指出了中国商业银行发展碳金融业务存在的七个主要障碍,进而提出了促进中国商业银行碳金融业务发展的对策建议。     

The detection of multiply charged dyes using matrix-assisted laser desorption/ionization mass spectrometry for the forensic examination of pen ink dyes directly from paper

Abstract:  Laser desorption mass spectrometry (LDMS) is emerging as a technique for questioned document examination. Its use is limited to detecting ink dyes that are neutral or singly charged. Several inks contain dyes that are multiply charged and LDMS cannot be employed for their identification. We have successfully detected >20 polyionic dyes that can be used in the manufacture of inks using matrix-assisted laser desorption/ionization (MALDI) MS, directly from paper, with the matrix, 2-(4-hydroxyphenylazo)benzoic acid (HABA), and the additive, diammonium hydrogen citrate (DAHC). For example, Acid Violet 49, a charged dye containing one positively-charged site and two negatively charged sulfonate groups, cannot be detected by LDMS, but forms intact, singly charged ions in the MALDI MS experiment. The method described is also useful for identifying multiply charged dye mixtures that are used in modern pen inks.     

The fate of the chemical warfare agent during DNA extraction

Forensic laboratories do not have the infrastructure to process or store contaminated DNA samples that have been recovered from a crime scene contaminated with chemical or biological warfare agents. Previous research has shown that DNA profiles can be recovered from blood exposed to several chemical warfare agents after the agent has been removed. The fate of four toxic agents, sulfur mustard, sodium 2-fluoroacetate, sarin, and diazinon, in a lysis buffer used in Promega DNA IQ extraction protocol was studied to determine if extraction would render the samples safe. Two independent analytical methods were used per agent, selected from GC-MS, 1H NMR, 19F NMR, (31)P NMR, or LC-ES MS. The methods were validated before use. Determinations were carried out in a semi-quantitative way, by direct comparison to standards. Agent levels in the elution buffer were found to be below the detectable limits for mustard, sarin, sodium 2-fluoroacetate or low (<0.02 mg/mL) for diazinon. Therefore, once extracted these DNA samples could be safely processed in a forensic laboratory.