Lorenzo Norma, Wan TianLang, Harper Ross J, Hsu Ya-Li, Chow Michael, Rose Stefan, Furton Kenneth G
Department of Chemistry and International Forensic Research Institute (IFRI), Florida International University, University Park, Miami, FL 33199, USA.
Anal Bioanal Chem. 2003 Aug;376(8):1212-24. doi: 10.1007/s00216-003-2018-7. Epub 2003 Jul 4.
This paper describes the use of headspace solid-phase microextraction (SPME) combined with gas chromatography to identify the signature odors that law enforcement-certified detector dogs alert to when searching for drugs, explosives, and humans. Background information is provided on the many types of detector dog available and specific samples highlighted in this paper are the drugs cocaine and 3,4-methylenedioxy- N-methylamphetamine (MDMA or Ecstasy), the explosives TNT and C4, and human remains. Studies include the analysis and identification of the headspace "fingerprint" of a variety of samples, followed by completion of double-blind dog trials of the individual components in an attempt to isolate and understand the target compounds that dogs alert to. SPME-GC/MS has been demonstrated to have a unique capability for the extraction of volatiles from the headspace of forensic specimens including drugs and explosives and shows great potential to aid in the investigation and understanding of the complicated process of canine odor detection. Major variables evaluated for the headspace SPME included fiber chemistry and a variety of sampling times ranging from several hours to several seconds and the resultant effect on ratios of isolated volatile components. For the drug odor studies, the CW/DVB and PDMS SPME fibers proved to be the optimal fiber types. For explosives, the results demonstrated that the best fibers in field and laboratory applications were PDMS and CW/DVB, respectively. Gas chromatography with electron capture detector (GC/ECD) and mass spectrometry (GC/MS) was better for analysis of nitromethane and TNT odors, and C-4 odors, respectively. Field studies with detector dogs have demonstrated possible candidates for new pseudo scents as well as the potential use of controlled permeation devices as non-hazardous training aids providing consistent permeation of target odors.
本文介绍了顶空固相微萃取（SPME）与气相色谱联用技术，用于识别执法认证的缉毒犬在搜寻毒品、爆炸物和人类时所警觉的特征气味。文中提供了多种可用缉毒犬的背景信息，本文重点研究的特定样本包括毒品可卡因和3,4-亚甲基二氧基-N-甲基苯丙胺（摇头丸）、爆炸物三硝基甲苯（TNT）和C4以及人体遗骸。研究包括对各种样本的顶空“指纹”进行分析和识别，随后对各个成分进行双盲犬类试验，以试图分离并了解犬类所警觉的目标化合物。已证明SPME-GC/MS在从包括毒品和爆炸物在内的法医样本顶空中提取挥发性物质方面具有独特能力，并且在协助调查和理解犬类气味检测这一复杂过程方面显示出巨大潜力。针对顶空SPME评估的主要变量包括纤维化学性质以及从数小时到数秒不等的各种采样时间，以及对分离出的挥发性成分比例的最终影响。对于毒品气味研究，CW/DVB和PDMS SPME纤维被证明是最佳的纤维类型。对于爆炸物，结果表明，在现场和实验室应用中最佳的纤维分别是PDMS和CW/DVB。配备电子捕获检测器的气相色谱（GC/ECD）和质谱（GC/MS）分别更适合分析硝基甲烷和TNT气味以及C-4气味。对缉毒犬的现场研究已经证明了新的假气味的可能候选物，以及可控渗透装置作为非危险训练辅助工具的潜在用途，该装置能够提供一致的目标气味渗透。
