| abstract |
A method of detecting the presence of substances in tissue from a subject comprises non-invasively removing tissue particulates from the exterior of the subject, eg. by vacuum collection of desquamated skin particles. The tissue particulates are then collected on a collection medium, for example filter paper, and subsequently analyzed to detect the presence of substances of interest. Such substances can be narcotics, explosives, etc. The substances sought may be detected by releasing them from the filter, for example by heating in an oven (4) to volatilize them, the vapour then being detected by means such as an ion mobility spectrometer (5). |