Detection of Metabolites of Trapped Humans Using Ion Mobility Spectrometry Coupled with Gas Chromatography

Abstract

For the first time, ion mobility spectrometry coupled with rapid gas chromatography, using multicapillary columns, was applied for the development of a pattern of signs of life for the localization of entrapped victims after disaster events (e.g., earthquake, terroristic attack). During a simulation experiment with entrapped volunteers, 12 human metabolites could be detected in the air of the void with sufficient sensitivity to enable a valid decision on the presence of a living person. Using a basic normalized summation of the measured concentrations, all volunteers involved in the particular experiments could be recognized only few minutes after they entered the simulation void and after less than 3 min of analysis time. An additional independent validation experiment enabled the recognition of a person in a room of ∼25 m(3) after ∼30 min with sufficiently high sensitivity to detect even a person briefly leaving the room. Undoubtedly, additional work must be done on analysis time and weight of the equipment, as well as on validation during real disaster events. However, the enormous potential of the method as a significantly helpful tool for search-and-rescue operations, in addition to trained canines, could be demonstrated.

Emission rates of selected volatile organic compounds from skin of healthy volunteers

“…1 create an initial library of potential skin-borne markers of human presence to be verified during field studies. Interestingly, five compounds from this list (acetone, n-hexanal, DL-limonene, n-octanal and n-nonanal) have recently been proposed as preliminary human markers during simulation experiments with entrapped volunteers involving ion mobility spectrometry [58].…”

Volatile organic compounds associated with Plasmodium falciparum infection in vitro

“…This compound was recently identified as a strong phyto-attractant of A. gambiae [18] and has been tested in mosquito baits [42]. Hexanal has been reported in several studies as a common marker in human breath and skin emanations, though these studies did not find it in the blood of healthy volunteers [41, 43–45]. Other technical approaches to the VOC content in humans, however, did find hexanal in normal plasma and breath, although at very low concentrations in comparison with the increased levels of hexanal connected to lung cancer patients [46–48], apparently linking its presence to cellular dysfunction or injury.…”

Potential of volatile organic compounds as markers of entrapped humans for use in urban search-and-rescue operations

“…Perhaps skin emission is promoted by the rapid diffusion of NH 3 via tissues resulting from the low molecular mass of this volatile. The usefulness of ammonia as an indicator of human presence was suggested by several authors [13,15]. Interestingly, the flux of this compound seems to differ between sleep and consciousness [15].…”