有机爆炸物的现场非介入性检测——顶空固相微萃取一真空气相色谱质谱法

本文考察了顶空固相微萃取在有机爆炸物现场非介入性检测中的适用性。由固相萃取（SPME）纤维头吸附的有机爆炸物用真空气相色谱一质谱联用仪进行检测。该方法所需的洗脱温度低，色谱分离时间短。SPME适用于提取蒸汽压不低于2．4，6-三硝基甲苯（TNT）的挥发性和半挥发性有机爆炸物，如较易挥发且不稳定的化合物三过氧化三丙酮（TATP）的非介入性检测就可以应用该方法。本研究使用静态顶空，尽可能地减少顶空体积，实现了较高的灵敏度。在现场，SPME方法的灵敏度受环境温度的影响较大：由于样品的蒸汽压未达到平衡，在固定顶空体积和萃取时间的条件下，SPME纤维头萃取的样品总量随温度的提高而增加。在有合适容器的情况下SPME纤维头上萃取的样品在取样3天后仍然能顺利检测。

Head space SPME sampling and vacuum outlet GC-MS for the non-invasive detection of organic explosives at the crime scene

The suitability of head space SPME （solid phase micro extraction） sampling for non-invasive detection of organic explosives at the crime scene is demonstrated. Vacuum outlet GC-MS is used for the analysis of the organic explosives materials absorbed on the SPME fiber. With this method low elution temperatures and short run times are achieved. Efficient SPME sampling is restricted to volatile and semi volatile organic explosives with vapor pressures equal to or higher than TNT （2,4,6-trinitrotoluene）. The methodology is very suited for the non-invasive detection of the relatively volatile and instable compound TATP （triacetone-triperoxide）. This work shows that the realization of a static head space with a minimized volume provides optimal sensitivity. Sensitivity is also strongly affected by the ambient temperature at the crime scene. At given volume and sampling time the amount absorbed at the SPME fiber increases with temperature due to non-equilibrium effects. With appropriate containers and holders, SPME fibers can be effectively analyzed up to 3 days after sampling.