MacCrehan William, Young Mimy, Schantz Michele, Angle T Craig, Waggoner Paul, Fischer Terrance
Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, USA.
Canine Performance Sciences Program, College of Veterinary Medicine, Auburn University, Auburn, AL, USA.
Forensic Chem. 2020 Dec;21. doi: 10.1016/j.forc.2020.100290.
Canine training aids based on vapor capture-and-release into a flexible polymer, polydimethylsiloxane (PDMS), have been used for in canine detection of explosives that have volatile or semi-volatile odorants. To enhance the rate of odor capture for less volatile targets, two temperatures are used for aid preparation. By using an elevated temperature for the target explosive, the amount of vapor is enhanced, increasing the production of the characteristic odor profile. The polymeric adsorbent is maintained at a cool temperature, favoring vapor capture. The success of this two-temperature approach is demonstrated for training aids targeting the low volatility explosive TNT using SPME (solid-phase microextraction) headspace analysis. In addition, the effect of using two temperatures on preparing training aids based on TNT and its more volatile impurities 2,4-DNT and 2,6-DNT are evaluated in canine trials. A thermal pretreatment to minimize the non-target odors in the PDMS polymer is presented.
基于将蒸汽捕获并释放到柔性聚合物聚二甲基硅氧烷（PDMS）中的犬类训练辅助工具，已被用于犬类检测具有挥发性或半挥发性气味剂的爆炸物。为了提高对挥发性较低目标的气味捕获率，在辅助工具制备过程中使用了两个温度。通过对目标爆炸物采用升高的温度，蒸汽量得以增加，从而增加了特征气味谱的产生。聚合物吸附剂保持在低温，有利于蒸汽捕获。使用固相微萃取（SPME）顶空分析法对以低挥发性爆炸物三硝基甲苯（TNT）为目标的训练辅助工具，证明了这种双温度方法的成功。此外，在犬类试验中评估了使用两个温度对制备基于TNT及其挥发性更强的杂质2,4 - 二硝基甲苯（2,4 - DNT）和2,6 - 二硝基甲苯（2,6 - DNT）的训练辅助工具的影响。还提出了一种热预处理方法，以尽量减少PDMS聚合物中的非目标气味。
