Detection of Explosives in Hair Using Ion Mobility Spectrometry

Abstract

Conventional explosives 2,4,6-trinitrotoluene (TNT), nitroglycerin (NG), and ethylene glycol dinitrate (EGDN) sorbed to hair can be directly detected by an ion mobility spectrometer (IMS) in E-mode (for explosives). Terrorist explosive, triacetone triperoxide (TATP), difficult to detect by IMS in E-mode, was detected in N-mode (for narcotics). Three modes of sample introduction to IMS vapor desorption unit were used: (i) placement of hair directly into the unit, (ii) swabbing of hair and placement of swabs (i.e., paper GE-IMS sample traps) into the unit, and (iii) acetonitrile extracts of hair positioned on sample traps and placed into the unit. TNT, NG, and EGDN were detected in E-mode by all three sample introduction methods. TATP could only be detected by the acetonitrile extraction method after exposure of the hair to vapor for 16 days because of lower sensitivity. With standard solutions, TATP detection in E-mode required about 10 times as much sample as EGDN (3.9 mug compared with 0.3 mug). IMS in N-mode detected TATP from hair by all three modes of sample introduction.

Levels of lead and cadmium in hair and saliva of school children in Ceres district, South Africa

“…However, since blood, saliva or urine analysis may exhibit different concentrations even though the sample is gathered at the same time as the hair, the analytical results for the hair analyzed should be considered carefully. The lack of a standard procedure for sample collection, washing, treatment and analytical quality control protocol arouses considerable resistance towards the reliability of hair analysis [30]. The aqua regia method of analysis is susceptible to acid interference, which makes it unreliable if used alone.…”

Ion spectrometric detection technologies for ultra‐traces of explosives: A review

“…Instead with 3 days exposure in narcotics mode of the instrument, the characteristic TATP peaks were detected. In conclusion, hair seems to be a suitable surface for explosive detection (Oxley et al, 2008). Studies on the optimization of IMS detection include collection efficiency for different particle sizes of TNT and a comparison of fingerprint and dry Teflon sampling systems of C4 containing RDX (Phares et al, 2000), the sizes of explosive residues prior to IMS analysis (Verkouteren, 2007), and the detection of smokeless powder from various surfaces like CD's and book covers (Colón et al, 2002) have been carried out.…”

Fast detection of triacetone triperoxide (TATP) from headspace using planar solid-phase microextraction (PSPME) coupled to an IMS detector

“…However, very few of these techniques can fully accomplish two important detection requirements: fast on-site analysis with unambiguous identification and low limits of detection from post-explosion debris with high selectivity. Ion mobility spectrometry (IMS) is another robust tool for the detection of TATP [6,[19][20][21][22] and has been used by law enforcement and homeland security in airports, government buildings, and at border crossings to detect explosives for several decades due to the characteristics of fast detection, high sensitivity, ease of use, and on-site analysis, making this detection system attractive over other techniques [23]. However, IMS has not been widely exploited for the detection of TATP, and limited research has been published due to the lack of efficient sampling methods that can be coupled to this instrument.…”