Nanoporous Silica Preconcentrator for Vapor-Phase DMNB, a Detection Taggant for Explosives
Nanoporous Silica Preconcentrator for Vapor-Phase DMNB, a Detection Taggant for Explosives
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DOI：
10.1021/acsomega.0c01615
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发表时间：
2020-07-28
期刊：
影响因子：
4.1
通讯作者：
Hutter, Tanya
中科院分区：
文献类型：
--
作者：
Day, Coco;Rowe, Nathan;Hutter, Tanya
在气相中检测痕量的爆炸物是非常重要的。分析物的预浓缩是降低现有传感器的检测限的有用技术。评价了纳米多孔二氧化硅（pSiO（2））基底作为气相2，3-二甲基-2，3-二硝基丁烷（DMNB）的预浓缩器，DMNB是法定添加到塑性炸药中的挥发性检测标记物。在pSiO（2）中收集后，DMNB蒸气在70 ℃下热解吸到气相色谱-质谱吸附管中。分析在pSiO（2）中收集的DMNB的总质量。pSiO（2）的负载时间和负载温度分别在15 - 60 min和5-20 ℃之间系统地变化。将预浓缩器的性能与作为对照的相同材料的无孔基材的性能进行比较。pSiO（2）的收集效率计算为在30分钟内通过其的总DMNB的约20%，在N-2载气中浓度为0.5ppm。在相同条件下，0.5和4.1 ppm DMNB分别与无孔基质的12和16相比具有增强因子。没有发现在装载阶段将pSiO（2）冷却到室温以下有什么好处，这消除了对冷却系统的任何需要，以帮助预浓缩。70摄氏度的低解吸温度是优于其他预浓缩系统的优点，尽管较高的温度可能会减少解吸时间。
The detection of trace amounts of explosives in the vapor phase is of great importance. Preconcentration of the analyte is a useful technique to lower the detection limit of existing sensors. A nanoporous silica (pSiO(2)) substrate was evaluated as a preconcentrator for gas-phase 2,3-dimethyl-2,3-dinitrobutane (DMNB), a volatile detection taggant added by law to plastic explosives. After collection in pSiO(2), the DMNB vapor was thermally desorbed at 70 degrees C into a gas chromatography-mass spectrometry sorbent tube. This was analyzed for the total mass of DMNB collected in pSiO(2). The loading time and loading temperature of pSiO(2) were varied systematically between 15 and 60 min and 5-20 degrees C, respectively. The preconcentrator's performance was compared to that of a nonporous substrate of the same material as a control. The collection efficiency of pSiO(2) was calculated as approximately 20% of the total DMNB that passed over it in 30 min, at a concentration of 0.5 ppm in N-2 carrier gas. It had enhancement factors compared to the nonporous substrate of 12 and 16 for 0.5 and 4.1 ppm DMNB, respectively, under the same conditions. No advantage was found with cooling pSiO(2) below room temperature during the loading phase, which removes any need for a cooling system to aid preconcentration. The low desorption temperature of 70 degrees C is an advantage over other preconcentration systems, although a higher temperature could decrease the desorption time.