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.     

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。     

关于突发公共事件处置中警方与媒体关系研究

在突发公共事件处置中,警方与媒体基于维护公共利益,在处置事件的各个方面须进行配合与协作,两者相互影响、相互制约。大众传播媒介通过收集有关警察组织形象的信息等方面对警察组织施加影响,警察组织通过警务信息公开等方式对大众传播媒介产生影响。警方与媒体在某些方面也存在着不一致,必然导致双方在某些方面的不和谐,甚至对抗和冲突。因此两者必须互信、合作,最终达到共赢的目标。     

在大型群众性活动安全保卫中如何做好服务群众工作

国家对群众性大型活动的安全管理工作以立法的方式加以调整,足以见得对群众性大型活动的高度重视。作为大型活动主管部门的政府机关——公安机关,必须不折不扣的贯彻执行《大型活动管理办法》,把《大型活动管理办法》中的服务群众立法宗旨,贯穿于大型活动保卫始终。在做好审查资质、安全许可、安全检查、安保指导的同时,必须做好大型活动现场的安全保卫工作。     

从革命党到执政党的转型——中共八大到十七大党代会报告及历届党章文本分析

经历了九十年的风雨激荡,中国共产党在时代的洪流中实践着自身的逐步转型.中国共产党从革命党到执政党的转型问题一直以来都是学界讨论的焦点问题.转型的逻辑、方式与表现都深刻地影响着中国政治道路的选择与国家的发展.从中共执政之后的历次党代会报告内容以及历届党章的文本分析中,找出中共转型的基本表征,理解中共转型的基本框架.     

群体性事件的理论探索

近年来群体性事件频发,引起了社会各界的广泛关注。由于受＂路径依赖＂和政治因素的影响,中国学术界对群体性事件的研究还只停留在描述和对策的层面,更没有形成较为成熟的理论;文章认为,群体性事件是现代化进程中社会的一个自然态,是一种动态的平衡。     

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.