Department of Nanoengineering, University of California-San Diego, La Jolla, CA 92093-0448, USA.
Anal Chim Acta. 2010 Feb 19;661(1):117-21. doi: 10.1016/j.aca.2009.12.008. Epub 2009 Dec 16.
This article reports on an integrated explosive-preconcentration/electrochemical detection system for 2,4,6-trinitrotoluene (TNT) vapor. The challenges involved in such system integration are discussed. A hydrogel-coated screen-printed electrode is used for the detection of the thermally desorbed TNT from a preconcentration device using rapid square wave voltammetry. Optimization of the preconcentration system for desorption of TNT and subsequent electrochemical detection was conducted yielding a desorption temperature of 120 degrees C under a flow rate of 500 mL min(-1). Such conditions resulted in a characteristic electrochemical signal for TNT representing the multi-step reduction process. Quantitative measurements produced a linear signal dependence on TNT quantity exposed to the preconcentrator from 0.25 to 10 microg. Finally, the integrated device was successfully demonstrated using a sample of solid TNT located upstream of the preconcentrator.
本文报道了一种用于 2,4,6-三硝基甲苯（TNT）蒸气的集成爆炸预浓缩/电化学检测系统。讨论了实现这种系统集成所面临的挑战。采用水凝胶涂覆的丝网印刷电极，使用快速方波伏安法检测从预浓缩装置中热解吸的 TNT。对预浓缩系统进行了优化，以实现 TNT 的解吸和随后的电化学检测，结果表明在 500 mL min(-1)的流速下，解吸温度为 120 摄氏度。在这种条件下，TNT 呈现出多步还原过程的特征电化学信号。定量测量结果表明，电化学信号与暴露于预浓缩器的 TNT 量之间呈线性关系，范围为 0.25 至 10 微克。最后，该集成装置在位于预浓缩器上游的固体 TNT 样品上成功进行了演示。
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