乳化炸药爆炸残留物分析

目的 探讨乳化炸药爆炸案件中导致爆炸残留物中铵根离子、硝酸根离子含量偏低的原因。方法 通过实际爆炸案例分析,实地了解乳化炸药制造工艺,采用离子色谱法检验爆炸案件及爆炸实验提取的残留物中铵根离子和硝酸根离子成分含量。通过与空白样本对比,分析导致乳化炸药爆炸残留物中铵根离子、硝酸根离子含量降低的原因。结果 经过生产工艺改进的乳化炸药爆炸后,其残留物中检出硝酸根和铵根离子的含量没有明显高于现场空白样本。结论 通过考察分析、对比检验,发现生产工艺改进是导致乳化炸药爆炸残留物中铵根离子和硝酸根离子含量偏低的原因。针对这一问题,本文提出了一些相应的解决方案。     

离子色谱法检测土制硝铵氯化炸药爆炸残留物中的氯酸根

本文建立了离子色谱-抑制电导检测测定含有高浓度硝酸根的爆炸尘土中残留氯酸根的方法。使用高容量阴离子分析柱IonPac AS19，以KOH为流动相，梯度淋洗，氯酸根在8min左右出峰，15min之内完成常规离子的分析，方法的检测限为2．67ng／ml（S／N=3）。方法的线性范围为0．01～1000μg／ml，线性相关系数为0．9998。模拟样品中1μg／mlClO3^-的峰面积相对标准偏差为0．98％，峰高的相对标准偏差为0．66％。将此法应用于两起爆炸案的爆炸尘土样品测定，加标回收率在99％以上。对主要干扰物离子硝酸根的研究发现，即使3000μg／ml的硝酸根对低浓度氯酸根（几个ppm级）的测定也不存在干扰，确保了测定结果的准确性。     

吸入TNT爆炸生成物导致急性中毒死亡1例

TNT学名2,4,6-三硝基甲苯,为无色或淡黄色带光泽针状晶体,工业品呈磷片状,有毒,味苦,多用于军事和地质勘查.笔者在临案检验中曾遇一起罕见的因吸入TNT爆炸生成物而导致急性中毒死亡的案例.报告如下: 一、案情介绍 1988年12月1日下午,本市射阳县合兴乡岗东组周训吉(男,11岁)放学回家后,称“去看炸鱼”而离家,后于当日十七时三十分左右,发现其死于江苏省石油地质调查288队行地下爆破测试的     

吸附管／气相色谱／质谱法分析纵火案的纵火剂残留物

用吸附管(AT)/气相色谱(GC)/质谱(MS)法检测纵火残留物中轻质矿物油是通过吸附管动态吸附检材中可挥发的有机物,然后通过热脱附将挥发物送至GC及GC/MS中检测。它既适用于轻组份的碳氢化合物,如汽油,也适用于较高分子的碳氢化合物,如柴油和煤油。用沸石预处理样品克服了样品中水分对鉴定的干扰。用本方法能够得到比过去所使用的溶剂提取法或顶空法(HS)更高的吸附效率和灵敏度,解决了以往由于残留物中热解产物干扰所造成的GC图形混乱复杂,难以准确分析鉴定的问题。用本方法分析纵火或火灾案件中常见的残留物-轻质矿物油,具有快速、灵敏、准确和简便等特点,可广泛应用于公安、司法和保险等各个领域。     

气体爆炸现场特征

近年来，可燃气体爆炸的事故和利用可燃气体实施爆炸犯罪的案件越来越多，虽然气体爆炸与凝聚相炸药爆炸同属化学爆炸，但两者的表现形式却有所不同，完全照搬炸药爆炸的理论及其规律应用于气体爆炸现场的勘查失于片面，因此，有必要从理论上对气体爆炸做更全面深入的研究。本文在气体爆炸理论的基础上，结合多年来勘查此类现场的实践，对气体爆炸现场的特征进行探讨，以便在环境和条件发生变化时，更准确、全面地勘查和分析现场。１气体爆炸机理当可燃气体或可燃液体的挥发性气体与空气按一定的比例混合，遇火源即发生爆炸，其机理可用热点…     

超分子溶剂萃取-气相色谱-串联质谱法检测尿液中苯二氮䓬类药物

目的建立一种尿液中9种苯二氮?类药物的超分子溶剂样品气相色谱-串联质谱(gas chromatography-tandem mass spectrometry,GC-MS/MS)分析方法。方法含9种苯二氮?类药物对照品的尿液样品用四氢呋喃和1-己醇组成的超分子溶剂进行液液萃取,取溶剂层氮吹至干,残余物用甲醇复溶后进行GC-MS/MS分析,数据采集方式为多反应监测模式,采用内标法定量。结果尿液中地西泮、咪达唑仑、氟硝西泮和氯氮平质量浓度在1~100ng/mL,劳拉西泮和阿普唑仑质量浓度在5~100ng/mL,硝西泮和氯硝西泮质量浓度在2~100ng/mL,艾司唑仑在质量浓度0.2~100ng/mL范围内具有良好的线性关系,相关系数为0.9991~0.9999,定量下限为0.2~5ng/mL,提取回收率为81.12%~99.52%,日内精密度[相对标准偏差(relative standard deviation,RSD)]和准确度(偏倚)分别小于9.86%、9.51%;日间精密度(RSD)和准确度(偏倚)分别小于8.74%、9.98%。室温和-20℃条件下,尿液中9种药物在15d内具有良好的稳定性。8名志愿者单摄口服阿普唑仑片后,在8~72h内尿液中阿普唑仑的质量浓度为6.54~88.28ng/mL。结论本研究建立的尿液中9种苯二氮?类药物的超分子溶剂萃取-GC-MS/MS分析方法,简便、快速、准确、灵敏,可为临床治疗及司法鉴定中苯二氮?类药物中毒监测提供技术支持。     

TATP检测的研究进展

近几年,由于TATP爆炸案件的频发,对TATP的检测需求导致一系列新的分析检测方法的产生。本文将介绍并讨论这些先进的检测方法 ,主要包括色谱、质谱等方法 ,并对这些方法的适用性进行评价。     

建立火场样品中汽油残留物ATD-GC-MS检验结果的评价方法

目的建立火场中汽油燃烧残留物ATD-GC-MS检验结果评价方法。方法将模拟燃烧样品用ATD-GC-MS法检验,检验结果通过对芳烃、烷烃、茚满、和萘系列的4个特征离子色谱图与已知汽油作比较,并利用向量夹角法计算样品与汽油色谱指纹图的相似度来对检验结果作评价。结果有汽油作助燃剂的模拟燃烧样品与汽油色谱指纹图的相似度一般大于90%,无汽油作助燃剂的样品则在60%以下。结论利用样品的4个特征离子色谱图与已知汽油作比较,并结合样品与汽油色谱指纹图相似度的计算,能对检验结果作出客观、可靠和准确的评价。     

氟乙酰胺和氟乙酸的毛细管柱气相色谱检测

本文建立氟乙酰胺和氟乙酸的毛细管柱气相色谱检测方法，氟乙酰胺和氟乙酸的线性检测范围为0．0625mg/ml～4mg／ml和0．625mg／ml~20mg／ml，最小检出浓度为31．25ug／ml和625ng/ml．太原地区地摊所售鼠药87．5％含有氟乙酰胺，30％含有氟乙酸．     

Dotmapping方法在超微量残留物检测中的应用

在法庭科学、刑事技术领域中,除了对特定的样品进行分析外,还经常遇到某一特殊物质是否存在的检验.如对射击残留物的检验,对剪切工具刃口部位特定物质的检验,对各种擦蹭部位特定物质的检验等.而后者检验的难度相对较大.特别对超微量残留物检测,必须在高放大倍率下进行检验.然而在高放大倍率下,分析视野相对较小,而且视野内大量灰尘、杂质颗粒对检验有很大干扰,如果将所有视野内的所有颗粒均进行元素分析,以确认当中是否有特定物质的残留颗粒,其工作量是十分巨大的甚至是不可能完成的.新型能谱仪的元素面分布图分析技术可以完成此项检验工作,但得到一幅元素面分布图至少需要几十分钟的时间,对于有近千个分析视野的检验来说,工作效率显然是很低的.     

毛细管电泳技术分析炸药残留物中无机离子

目的　建立炸药残留物中无机离子的毛细管电泳检测方法。方法　运用缓冲溶液使无机离子在毛细管电泳中达到分离 ,采用紫外间接检测法分析。结果　该方法可从爆炸残留物中准确检测出无机阴离子 (Cl- 、SO2 - 4、NO- 2 、NO- 3、ClO- 3和ClO- 4离子 )和无机阳离子 (NH 4、K 、Na 和Mg2 离子 )。结论　操作方法简便快捷 ,检材用量少 ,检测极限可达ng/ml级 ,分析结果满意     

Determination of elemental sulfur in explosives and explosive residues by gas chromatography-mass spectrometry

A new method for the positive identification of elemental sulfur in explosives and explosive residues is developed. Following a carbon disulfide wash of explosives or explosive residues, a sample of the extracted material is injected onto a gas chromatography (GC) column, then analyzed via mass-selective (MS) detection. A positive identification of elemental sulfur is based on both retention time and fragmentation pattern. The GC-MS method is demonstrated to be useful in detecting and positively identifying elemental sulfur from both burned and unburned explosive mixtures. With a detection limit of 2.5 ng (2.5 x 10(-9) grams) of elemental sulfur on the column, it is shown to be 400 times more sensitive than the presumptive chemical color test that is currently the method employed for detection of small amounts of sulfur.     

Chemical signature of ecstasy volatiles by comprehensive two-dimensional gas chromatography

A method for ecstasy volatiles 'signature' analysis based on two-dimensional gas chromatography separation and time-of-flight mass spectrometry detection (GC×GC-TOFMS) is presented. Organic impurity volatiles were extracted by head space solid phase microextraction (HS-SPME). The final column phase choice of the four different column combinations tested was a low-polarity 5% phenyl polysilphenylene-siloxane coupled with a polyethylene glycol phase, which best displayed the complex impurity profile. Second dimension ((2)D) retention time reproducibility was found to be about 1% RSD, and area reproducibility of SPME sampling was just over 5% RSD for compounds with S/N ratio of about 100. High similarity of TOFMS spectra of impurities was obtained against commercial MS libraries. 16 components from the two-dimensional profiles were selected for comparison of the 24 ecstasy tablets, most of which proved to be benzodioxole derived compounds. All tablets were correctly classified in eight groups according to their post-tabletting characteristics, when appropriate data pre-treatment was applied. Principal component analysis revealed clustering of samples according to the country of origin. Samples from Macedonia were elevated in N-formyl-MDMA and N-acetyl-MDMA while samples from Australia were elevated in 3,4-methylenedioxypropane and 3,4-methylenedioxyacetophenone. Furthermore, three components were found to be unique for one of the source countries. The additional separation of components on the (2)D column, increased response due to modulation, high acquisition rate with full mass spectra using TOFMS detection, and MS deconvolution extend the possibility of detecting additional markers and route-specific components, especially of low abundant, polar components.     

Detection of acetic acid in cadavers by gas chromatography

A simple technique of sample preparation for gas chromatographic test for acetic acid in cadaveric material has been developed. The background concentration of natural content of acetates in the stomach, liver and kidneys are determined. The error of the method is no more than 10% with standard deviation +/- 0.04-0.13.     

Forensic analysis of ignitable liquids in fire debris by comprehensive two-dimensional gas chromatography

The application of comprehensive two-dimensional gas chromatography (GC x GC) for the forensic analysis of ignitable liquids in fire debris is reported. GC x GC is a high resolution, multidimensional gas chromatographic method in which each component of a complex mixture is subjected to two independent chromatographic separations. The high resolving power of GC x GC can separate hundreds of chemical components from a complex fire debris extract. The GC x GC chromatogram is a multicolor plot of two-dimensional retention time and detector signal intensity that is well suited for rapid identification and fingerprinting of ignitable liquids. GC x GC chromatograms were used to identify and classify ignitable liquids, detect minor differences between similar ignitable liquids, track the chemical changes associated with weathering, characterize the chemical composition of fire debris pyrolysates, and detect weathered ignitable liquids against a background of fire debris pyrolysates.     

全二维气相色谱在刑事技术中的应用

综述了近年来发展起来的全二维气相色谱(GCхGC)技术正交分离系统原理及其特点以及在刑事技术中应用的发展前景。     

Fast gas chromatography of explosive compounds using a pulsed-discharge electron capture detector

The detection of a mixture of nine explosive compounds, including nitrate esters, nitroaromatics, and a nitramine in less than 140 sec is described. The new method employs a commercially available pulsed-discharge electron capture detector (PDECD) coupled with a microbore capillary gas chromatography (GC) column in a standard GC oven to achieve on-column detection limits between 5 and 72 fg for the nine explosives studied. The PDECD has the benefit that it uses a pulsed plasma to generate the standing electron current instead of a radioactive source. The fast separation time limits on-column degradation of the thermally labile compounds and decreases the peak widths, which results in larger peak intensities and a concomitant improvement in detection limits. The combination of short analysis time and low detection limits make this method a potential candidate for screening large numbers of samples that have been prepared using techniques such as liquid-liquid extraction or solid-phase microextraction.     

Detection of methadone in human hair by gas chromatography/mass spectrometry

Determination of methadone in human hair by gas chromatography/mass spectrometry was described. Helium as carrier gas, a 30-m bonded phase-fused silica DB-1 capillary column and splitless injection at 230 degree C temperature were used. The concentrations of methadone and its metabolites were measured in addition by radioimmunoassay (RIA). Both methods GC/MS and RIA showed the presence of methadone in human hair.     

Systematic analysis of explosive residues.

A scheme for systematic analysis of explosive residues is presented and demonstrated by test explosions using commercial, military, and homemade explosives. The significance of reaction product identification is demonstrated.     

Detection of malathion in a victim by gas chromatography/negative ion chemical ionization mass spectrometry

We experienced an autopsy case in which a 53-year-old woman committed suicide by ingesting allegedly a certain agricultural chemical. The blood and stomach contents, after extraction with acetonitrile and chloroform, were subjected to analysis by gas chromatography (GC)/negative ion chemical ionization (CI) mass spectrometry (MS). By total ion monitoring in the negative CI mode, a large peak appeared. The mass spectrum of the peak showed a strong anion at m/z 157, suggesting the presence of an organophosphorus pesticide. By measuring its spectrum in the positive electron impact (EI) mode, it was identified as malathion. The selected ion monitoring in the negative CI mode showed that the malathion peak was not interfered with by any impurities, and its background was very low. The sensitivity in the negative CI mode was about 5-10 times higher than that in the positive EI mode. Our data show that the GC/negative ion CI MS is useful for both screening and sensitive quantitation of organophosphorus pesticides.