Analytical Chemistry Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States.
Anal Chem. 2011 Nov 15;83(22):8560-5. doi: 10.1021/ac201888r. Epub 2011 Oct 28.
The vapor-time profiles of explosive materials are of valuable interest to Homeland Security, providing critical information that can aid in the detection of explosive-containing devices. An approach is described that achieves reproducible characterization of volatile components as a function of time based on comparison of the sample response to an externally sampled internal standard (ESIS). Utilizing nonequilibrium solid-phase microextraction (SPME) measurements, this SPME-ESIS technique improves reproducibility (reported as percent relative standard deviation) of vapor-time profiles by approximately an order of magnitude and allows for an equitable comparison of the target compound between diverse materials. Two odorants associated with canine detection of explosives, 2-ethyl-1-hexanol and 2,4-dinitrotoluene, are used to optimize parameters for the SPME-ESIS technique.
爆炸物的蒸气时间分布对于国土安全具有重要意义，为检测含爆炸物的装置提供了关键信息。本文描述了一种方法，通过将样品的响应与外部取样的内标（ESIS）进行比较，实现了挥发性成分随时间变化的可重现特征化。利用非平衡固相微萃取（SPME）测量，该 SPME-ESIS 技术将蒸气时间分布的重现性（以相对标准偏差的百分比表示）提高了约一个数量级，并允许在不同材料之间对目标化合物进行公平比较。两种与犬类探测爆炸物相关的气味剂，2-乙基-1-己醇和 2,4-二硝基甲苯，用于优化 SPME-ESIS 技术的参数。
