固相微萃取-气相色谱-质谱法测定火场残留物中白酒类助燃剂北大核心CSCD

白酒主要指中国白酒。白酒是含乙醇较高的一种水溶性液体饮料,其主要成分是乙醇、水,极少的成分是酸、酯、醇、醛等有机化合物。白酒的种类繁多,乙醇含量较高的白酒有良好的燃烧性能,可被犯罪分子用来作为放火的助燃剂,因此目前对白酒类助燃剂的正确分析鉴定对于放火案件的侦破具有非常重要的意义。火场残留物中白酒类物质的提取和鉴定向来是火场助燃剂提取鉴定技术的难题。     

固相微萃取-气相色谱-质谱法测定火场残留物中白酒类助燃剂

正白酒主要指中国白酒。白酒是含乙醇较高的一种水溶性液体饮料,其主要成分是乙醇、水,极少的成分是酸、酯、醇、醛等有机化合物。白酒的种类繁多,乙醇含量较高的白酒有良好的燃烧性能,可被犯罪分子用来作为放火的助燃剂,因此目前对白酒类助燃剂的正确分析鉴定对于放火案件的侦破具有非常重要的意义。火场残留物中白酒类物质的提取和鉴定向来是火场助燃剂提取鉴定技术的难题。由于火灾现场通     

典型塑料载体与助燃剂燃烧残留物的闪蒸气相色谱-质谱分析

通过对火场常见塑料载体与助燃剂混合燃烧残留物的分析,发展一种适用此类燃烧残留物的火灾物证鉴定方法,对火场中是否存在助燃剂进行判断,避免漏检情况的发生。应用热分析技术确定合适的闪蒸温度,在此温度下对塑料载体与助燃剂混合燃烧残留物进行闪蒸分析,并从实验条件选择、可行性分析、定性分析三方面对闪蒸技术进行评价。结果表明,闪蒸气相色谱-质谱（Flash GC-MS）技术可以检测到热塑性聚合物塑料载体与助燃剂混合燃烧残留物中残留的助燃剂特征组分,可对火场中是否存在过助燃剂进行辨别。闪蒸气相色谱-质谱技术丰富了现代火灾物证鉴定技术,能进一步辅助火灾物证鉴定工作,使鉴定结论更准确、可靠。     

不同型号的汽油燃烧残留物的薄层色谱分析

将93、97汽油作为研究对象,模拟火灾现场条件制备了完全燃烧的火场残留物,采用薄层色谱扫描技术对燃烧残留物中两种不同型号汽油的特征进行了实验研究,其研究结果对判断火场中是否有汽油参与燃烧有一定的指导作用,可以为消防部队放火火灾的调查提供一种物证鉴定手段,为放火火灾原因认定提供科学的理论依据,亦能为我国火场可燃液体鉴定标准的建立提供参考。     

裂解气相色谱-质谱分析火场残留物中助燃剂

通过对火灾现场助燃剂及其燃烧残留物进行分析，开展了基于裂解气相色谱-质谱法（PyGC-MS）的火场助燃剂分析方法。选取了汽油和柴油2种助燃剂以及棉布和聚对苯二甲酸乙二醇酯（PET）塑料2类载体，制备了助燃剂与载体的混合燃烧残留物。利用热分析技术确定样品的特征性温度，并对分析条件进行优化与选择。通过闪蒸分析和裂解分析的分步裂解方法，对样品进行了PyGC-MS分析。实验结果表明，PET载体原样燃烧残留物的裂解产物共有35个组分，而PET载体与汽油混合燃烧残留物和PET载体与柴油混合燃烧残留物的裂解产物只有25个组分，且各裂解产物的种类和含量均不相同。该法可对同一载体的自身燃烧残留物和与助燃剂混合燃烧残留物进行区分，适用于火灾残留物中助燃剂的分析，可对火场中是否存在助燃剂进行判别，为火灾性质的判断和火灾调查工作提供科学依据。     

火场燃烧残留物检验鉴定方法研究进展

火场燃烧残留物的检验鉴定涉及浓缩、前处理及实验室鉴定等多个环节,同时火场高度的破坏性和暴露性,造成燃烧残留物成分分析存在较多干扰.为提高火场燃烧残留物检验鉴定的准确性和实效性,国内外学者围绕检验鉴定方法进行了研究和探索.为此,对相关研究进行了梳理,特别是对现场快速检验、现场浓缩、实验室前处理和实验室分析检验新方法进行了总结归纳,旨在为火场燃烧残留物物证的检验鉴定提供参考.     

火灾现场残留物中助燃剂提取及检测方法研究进展

综述了近10年来火灾现场助燃剂残留物的提取及检测方法,并对火场助燃剂残留物的检测进行了展望.     

Fisher判别在气相色谱-质谱分析助燃剂燃烧残留物中的应用

为寻找一种用于火场助燃剂燃烧残留物鉴定的更为准确、有效的模式识别方法,对7种常见助燃剂在不同载体上的燃烧残留物样品及未知送检样品进行气相色谱-质谱（GC-MS）分析测试,通过特征组分分析鉴定出未知样品中含有汽油成分。同时运用Fisher判别及PCA（主成分分析）/Fisher判别联用两种判别方法对样本数据进行了分析处理,PCA/Fisher判别联用的结果表明送检样本中含有硝基油漆稀料成分,而仅使用Fisher判别的结果表明送检样本中含有93^#汽油。通过将两种分析方法所得结果与GC-MS特征组分分析的结果进行比对发现,Fisher判别能够对7种助燃剂燃烧残留物的样本实现更有效的分类,对未知样本的判别更为有效。该研究结果为火场助燃剂鉴定提供了新的数据分析手段。     

化学计量学应用在助燃剂检验鉴定中的研究进展北大核心CSCD

化学计量学已广泛应用于法庭科学领域的数据处理和分析,尤其是物证的物理和化学检验。为了解其在助燃剂检验鉴定领域应用的研究进展,将近年来比较有代表性的国内外相关研究进行了综述,分别总结了化学计量学在助燃剂检验鉴定中定性、分类及物证证据效力评价方面的应用,包括助燃剂检验鉴定中干扰的排除、助燃剂种类的区分以及似然比的计算等,并对其应用前景进行了展望(引用文献49篇)。     

闪蒸气相色谱法应用于天然纤维与助燃剂混合燃烧残留物的分析

应用闪蒸气相色谱法对2种火场中常见的天然纤维载体(木材和棉布)与汽油(或柴油)的混合燃烧残留物进行分析。在模拟火场条件下,分别制得2种载体与汽油或柴油混合燃烧的残留物。根据燃烧残留物热重分析结果选择闪蒸温度为300℃。分析对象为上述2种载体分别在无助燃剂和有助燃剂条件下共同燃烧得到的残渣,分别在完全燃烧后0,24,72h进行取样。结果表明:闪蒸气相色谱技术可从混合燃烧残留物中检测到助燃剂的特征组分,能够满足助燃剂检测鉴定的要求。随着取样时间的延长,助燃剂发生挥发,残留特征组分减少。棉布载体燃烧残留物比木材载体燃烧残留物对助燃剂特征组分的保留效果更好。柴油燃烧产物特征组分较汽油特征组分保留时间更长。     

Determination of gasoline and diesel residues on wool,silk, polyester and cotton materials by SPME–GC–MS

The identification of ignitable liquids is very important and challenging aspect in arson crime investigations. The detection of gasoline and diesel fuel components using solid phase micro-extraction prior to gas chromatography–mass spectrometry for the forensic analysis of fire debris has been carried out. Previous works show that the absorption characteristics of the substrate are one of the most important factors in determining the evaporation rate of the accelerants. In order to determine the presence of the fuel residues, four of the most common substrate materials were tested in this work; wool, cotton, silk and polyester. The obtained results indicate that both gasoline and diesel fuel accelerants persisted longer on wool and silk than on the other selected substrates. Such information illustrates the influence of fuel persistence times after extinguishing and the best materials to be scanned for ignitable liquids at the fire scene.     

Study of acidified ignitable liquid residues in fire debris by solid‐phase microextraction with gas chromatography and mass spectrometry

The detection and identification of ignitable liquid residues in fire debris can be meaningful in fire investigations. However, background pyrolysis products and weathering hinder the identification and classification steps. In addition to those processes, the acidification of the ignitable liquids before the combustion process could make those tasks even more difficult. Nevertheless, there are no systematic studies assessing the extraction, analysis, and composition of acidified ignitable liquid residues obtained from fire debris. In this work, a method for the study of acidified ignitable liquid residues in fire debris by solid‐phase microextraction with gas chromatography and mass spectrometry is proposed. This methodology has been evaluated, first with simulated solutions (gasoline/sulfuric acid mixtures set on fire under controlled conditions), and then with analysis of samples from real fire debris obtained from 18 chemical ignition Molotov cocktails made with sulfuric acid and three different ignitable liquids (two types of gasoline and diesel fuel). In addition, the extensive modifications observed in chromatograms of acidified ignitable liquid residues regarding neat and weathered samples were studied. These alterations were produced by the combustion and acidification processes. As a consequence, tert‐butylated compounds are proposed as diagnostic indicators for the identification of acidified gasoline in fire debris, even in strongly weathered samples.     

基于广义回归神经网络的微生物降解效应对助燃剂检测的影响

为探究火场土壤载体中微生物降解效应对助燃剂鉴定的影响，在普通土和培养土两种土样上注射助燃剂，以密封存放时间为变量，通过静态顶空的样品预处理方式对样品内的助燃剂残留物进行气相色谱-质谱法（GC-MS）鉴定。研究发现，微生物降解效应会改变样品内助燃剂组分，不同土样内降解结果有所不同，普通土样的降解效应较培养土样明显，C9~C12直链烷烃和单取代芳香烃更易被降解，多取代芳烃的降解难度随取代基含量的增多而增加。按土样种类采用主成分分析（PCA）的方式进行数据降维后，采用广义回归神经网络（GRNN）对不同土样结果区分，准确率达100%。     

Identification of petroleum distillates from fire debris using multidimensional gas chromatography

Summary A method for identifying petroleum distillates (accelerants) in fire debris samples by dynamic headspace analysis and multidimensional gas chromatography is described. The method relies on the separation of target compounds characteristic of different petroleum distillate classes from interfering co-eluting and matrix components. A relatively nonpolar column is used to characterize the volatility distribution of the sample and heartcutting to a second polar column of certain fractions to separate target compounds from interferences unresolved on the first column. The method is demonstrated for the identification of gasoline, kerosene, charcoal lighter fluid, and paint thinners in simulated arson samples.     

一种改进的SPME方法提取火场残留物中的促燃剂

对当前国内外用于火场残留物中促燃剂的提取方法进行研究,包括采用活性炭片法(ACS)、固相微萃取(SPME)以及对固相微萃取技术从传统的热解吸模式到溶剂脱附模式的扩展性思考。通过提取3种促燃剂(汽油,煤油和柴油)检材的效能比较与分析,优化了实验条件,确定了SPME的提取和溶剂脱附的方法,实验研究表明,SPME-溶剂脱附法是火场促燃剂残留物分析的有效方法之一。     

Recent advances in the applications of forensic science to fire debris analysis

The forensic discipline of ignitable liquid and fire debris analysis is rapidly changing. Refinements in existing methods as well as development of new techniques are changing the routine methods of analysis. Optimization of existing extraction techniques and research into novel methods of extracting debris have improved the recovery of ignitable liquids from debris samples. The application of highly specialized instrumentation to problems of sensitivity and matrix interference has resulted in new ways of performing chemical analyses, allowing for improved limits of detection. Preliminary research in novel approaches to ignitable liquid comparisons is being evaluated, with the hopes of providing more detailed information to the field investigators. Research into a variety of areas related to fire debris analysis is ongoing, and will continue to improve the quality of ignitable liquid residue analysis.     

Using the tools of chromatography,mass spectrometry,and automated data processing in the detection of arson

The analysis of residual accelerants in fire debris is commonly carried out by a three-step procedure: sample preparation; separation and detection; and data interpretation. Each of these steps can be optimized individually but successful analysis requires that they are compatible with each other. The isolation of residual accelerant from fire debris requires that several methods are used to cover the range of fueis that are commonly used by arsonists. Since almost all incendiary fires are set with petroleum based fuels such as gasoline or heating oil, analysis is targeted toward hydrocarbons. Capillary column gas chromatography on apolar phases is now the overwhelmingly predominant method of separation. Data interpretation is commonly carried out by visual comparison of chromatograms. Fire debris analysis presents some unique challenges that are not often encountered in other fields. The analyte may be present at only trace levels and pyrolysis products from building materials or furnishings may dominate chromatographic patterns. Synthetic polymers may act as precursors to hydrocarbons that compete with substances typically found in petroleum based fuels. Exposure to heat and other environmental factors may also generate severe distortions in the chromatographic profiles of accelerants. Unfortunately, there is no simple solution to these problems. Methods are available to reduce some of the chemical noise introduced by interferences and thus enhance the recognizability of the target substances. Mass spectrometry, in combination with a modern data system, is the most effective approach to filter out unwanted substances. The interpretation of the analytical results is aided by scaling, side-by-side comparison, or stacking of chromatograms. An additional advantage of such computerized systems is the possibility of complete automation of the analysis. In this communication, we look at the interplay of chromatographic resolution, noise reduction by mass spectrometry, and automated data evaluation. Examples from model experiments and from simulated arson samples are presented.     

A Forensic Approach to Evaluate the Effect of Different Matrices and Extraction Solvents for the Identification of Diesel Residue in Simulated Arson by GC–MS

Chromatographia - Investigation of an arson case presents several challenges to the forensic investigator. Identification of the ignitable liquid residues in the fire debris is one of the crucial...