Trace explosives sensor testbed (TESTbed)

Abstract

A novel vapor delivery testbed, referred to as the Trace Explosives Sensor Testbed, or TESTbed, is demonstrated that is amenable to both high- and low-volatility explosives vapors including nitromethane, nitroglycerine, ethylene glycol dinitrate, triacetone triperoxide, 2,4,6-trinitrotoluene, pentaerythritol tetranitrate, and hexahydro-1,3,5-trinitro-1,3,5-triazine. The TESTbed incorporates a six-port dual-line manifold system allowing for rapid actuation between a dedicated clean air source and a trace explosives vapor source. Explosives and explosives-related vapors can be sourced through a number of means including gas cylinders, permeation tube ovens, dynamic headspace chambers, and a Pneumatically Modulated Liquid Delivery System coupled to a perfluoroalkoxy total-consumption microflow nebulizer. Key features of the TESTbed include continuous and pulseless control of trace vapor concentrations with wide dynamic range of concentration generation, six sampling ports with reproducible vapor profile outputs, limited low-volatility explosives adsorption to the manifold surface, temperature and humidity control of the vapor stream, and a graphical user interface for system operation and testing protocol implementation.

Non‐contact detection of fentanyl by a field‐portable ion mobility spectrometer

“…For vapor mode LOD, the TESTbed system was used. This vapor delivery system has demonstrated the ability to deliver both high and low volatility explosives and narcotics vapor 16 . The system enabled the delivery of NPPA vapor at specific concentrations in air where the nominal NPPA mass delivered was calculated based on the total volume of air sampled.…”

“…The system produces a continuous stream of trace analyte vapor that can then be tested via a multiport manifold. Analyte concentration is monitored via gas chromatography–mass spectrometry (GC–MS) 16 . Briefly, a NPPA standard was prepared to 2 mg ml −1 in methanol.…”

“…The GC column oven began at 30°C, was held for 30 s, increased to 240°C at 50°C/min, and finally held at 240°C for 15 s. The transfer line to the MS was 250°C and the MS was operated in Selective Ion Mode (SIM). More details on the set‐up and function of the TESTbed can be found in Collins et al 16 …”

“…Analyte concentration is monitored via gas chromatography-mass spectrometry (GC-MS). 16 Briefly, a NPPA standard was prepared to 2 mg ml À1 in methanol. From this standard solution aqueous solutions were prepared in 50-ml centrifuge tubes at concentrations ranging from 0.3-13.5 mg L À1 .…”

AP4.4 - Trace Vapor Testbed and Vapor Generators for Hazardous Chemicals, Explosives and Narcotics

“…The TESTbed has been demonstrated for explosives, narcotics and toxic industrial chemicals, including extenisve studies of the following explosives: nitromethane (NM), nitroglycerine (NG), ethylene glycol dinitrate (EGDN), triacetone triperoxide (TATP), 2,4,6trinitrotoluene (TNT), pentaerythritol tetranitrate (PETN), and hexahydro-1,3,5-trinitro-1,3,5triazine (RDX). [1] An on-line validation system attached to a sample port provides near real-time verification of the explosives from part-permillion (ppm) to part per quadillion (ppq) levels, see Figure 3. Fig.…”