共查询到16条相似文献,搜索用时 250 毫秒
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目的为火场样品中痕量汽油残留物的检测建立一种简便、高灵敏度的检验方法和可靠的检验结果评判方法。方法用TenaxTA吸附管吸附富集火场样品中的汽油成分,然后用ATD—GC—MS法自动解吸和检测。通过模拟燃烧实验,探讨了检验结果的评判方法:根据样品的m/z(57+85)、m/z(91+105+119)、m/z(117+131)和m/z(128+142+156)四个质量色谱图与已知汽油作比较来对检验结果作评判。结果6组模拟燃烧实验中凡有汽油作助燃剂的样品.均检出汽油残留物成分。结论所建立的方法具有操作简便,检测灵敏度高,杂质干扰少,定性结论准确可靠等特点。可用于实际火场样品中痕量汽油残留物的检测。 相似文献
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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。 相似文献
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GC/MS/MS时间编程在火灾现场助燃剂检测中的应用 总被引:4,自引:0,他引:4
运用Varian SATURN2000气质联用仪通过GC/MS、GC/MS/MS、时间编程 GC/MS/MS对汽油样品进行分析比对,发现利用时间编程GC/MS/MS,对检测火灾现场残留汽油效果很好,可彻底排除样品中基体的背景干扰,大大提高检测灵敏度;同时对混合助燃剂(汽油+煤油、汽油+柴油)进行了实验探索。 相似文献
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目的建立检验纵火案件现场燃烧残留物中助燃剂的一种方法。方法利用固相微萃取器吸附浓缩燃烧残留物中的挥发性气体,使用气相色谱仪对挥发性气体进行定性分析。结果固相微萃取与气相色谱仪联用能较好地对火场不同介质燃烧残留物中汽油、煤油、柴油等助燃剂进行种类认定。结论该方法简便易行。 相似文献
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Intratracheal gas analysis was carried out by gas chromatography/mass spectrometry (GC/MS) in 20 burned body cases (13 males and 7 females). Volatile aromatic and aliphatic hydrocarbons were detected by GC/MS using a GS-Q column with the intratracheal gas as well as the blood in 19 cases. The characteristic patterns of mass chromatograms for gasoline, kerosene (gas oil), and liquid petroleum gas could be differentiated from each other using the intratracheal gas. The burned body in one case showed no presence of volatile substances in the intratracheal gas, nor intratracheal soot, although high concentrations (1 microg/g and more) of volatile substances were detected on the clothes. The victim also had normal CO-Hb concentrations (0.1 to 0.2%) in the heart blood. The results of intratracheal gas analysis were consistent with signs of the vital reaction. In conclusion, intratracheal gas analysis provides a supportive method for diagnosing the cause of death in burned bodies, and yields for at least 48 hours valuable information on volatile hydrocarbons (being detected in deliberate or accidental fire cases) to which the body had been exposed just before death. 相似文献
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A solid-phase microextraction (SPME) procedure involving direct contact between the SPME fibers and the solid matrix and subsequent gas chromatography/mass spectrometric analysis for the detection of accelerants in fire debris is described. The extraction performances of six fibers (100 mum polydimethylsiloxane, 65 mum polydimethylsiloxane-divinylbenzene, 85 mum polyacrylate, 85 mum carboxen-polydimethylsiloxane, 70 mum Carbowax-divinylbenzene, and 50/30 mum divinylbenzene-Carboxen-polydimethylsiloxane) were investigated by directly immersing the fibers into gasoline, kerosene, and diesel fuel. For simulated fire debris, in the direct contact extraction method, the SPME fiber was kept in contact with the fire debris matrix during extraction by penetrating plastic bags wrapping the sample. This method gave comparable results to the headspace SPME method in the extraction of gasoline and kerosene, and gave an improved recovery of low-volatile components in the extraction of diesel fuel from fire debris. The results demonstrate that this procedure is suitable as a simple and rapid screening method for detecting ignitable liquids in fire debris packed in plastic bags. 相似文献
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Lu W Rankin JG Bondra A Trader C Heeren A Harrington Pde B 《Forensic science international》2012,220(1-3):210-218
The gasoline and kerosene collected from different locations in the United States were identified by gas chromatography/mass spectrometry (GC/MS) followed by chemometric analysis. Classifications based on two-way profiles and target component ratios were compared. The projected difference resolution (PDR) mapping was applied to measure the differences among the ignitable liquid (IL) samples by their GC/MS profiles quantitatively. Fuzzy rule-building expert systems (FuRESs) were applied to classify individual ILs. The FuRES models yielded correct classification rates greater than 90% for discriminating between samples. PDR mapping, a new method for characterizing complex data sets was consistent with the FuRES classification result. 相似文献
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A new, fast, and ultra-sensitive headspace sampling method using the Capillary Microextraction of Volatiles (CMV) device is demonstrated for the analysis of ignitable liquid residues (ILRs) in fire debris. This headspace sampling method involves the use of a heated can (60°C) to aid in the recovery of volatile organic compounds (VOCs) from medium and heavy petroleum distillates. Our group has previously reported the utility of CMV to extract gasoline at ambient temperature in less than 5 min in the field. This work evaluates the recovery and analysis of low mass loadings (tens of ng) of VOCs from charcoal lighter fluid, kerosene, and diesel fuel. Nonane, decane, undecane, tridecane, tetradecane, and pentadecane were selected for evaluation of recovery to represent these ILR classes. The face-down heated can headspace sampling technique was compared to the previously reported, non-heated, paper cup headspace sampling technique. Mass recovery improvements of 50%–200% for five of the six target compounds in diesel fuel were achieved compared to the non-heated sampling method. The average relative standard deviation (reported as % RSD) between the replicate trials decreased from an average of 28% to 6% when using the heated can method. Ignitable liquids were spiked onto burned debris in a live burn exercise and sampled using the heated can and paper cup headspace sampling techniques. The heated sampling technique reported here, for the first time, demonstrates an effective extraction method that when coupled to a portable GC–MS instrument allows for a sampling and analysis protocol in the field in less than 30 min. 相似文献
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Kocisko MJ 《Journal of forensic sciences》2001,46(2):356-362
Clear plastic bags are often used for the collection, sampling and storage of ignitable liquid evidence. They are popular because they are easy to store. transport and are inexpensive. Cryovac and Globus brand polyethylene/polyvinylidine dichloride bags were tested for suitability in storing ignitable liquid evidence. Standards of diesel, kerosene and gasoline were placed in the bags and sampled by passive headspace adsorption. The bags were then heated to determine if absorbed components of the standards could be released upon heating. Recovered extracts were analyzed by GC and GCMS. These bags were found to absorb components of diesel, kerosene, and gasoline. and were also found to produce interfering by-products that obstruct the chromatographic results. Evidence containers need to be tested to ensure that low levels of ignitable liquids are not missed. 相似文献