98/04297 Method and device for detecting unburnt carbon in fly ashes from coal firing boiler by using micro wave

Abstract

The detection of ignitable liquid residues (ILR) on samples related to fire scenes provides investigators with important information. Field test kits were developed as an alternative procedure to swabbing using cotton wool and cotton tip applicators for situations where direct sampling is not possible. Central to the kits is a piece of white absorbent non-woven material consisting of polypropylene fibres (cloth). Experiments were carried out in our laboratory using the polypropylene cloths and cotton wool for collection of burnt and unburnt petrol residues from porous and non-porous surfaces. Every aspect of this new procedure was validated, involving more than 200 analyses of fire debris samples, where the polypropylene cloth was used to sample ILR comprising all common accelerants. The use of field test kits for collection of petrol and medium petroleum distillate (MPD) residues from hands was validated on the hands of 11 volunteers. The polypropylene cloth was found to be suitable for application in field test kits for the collection and recovery of petroleum-based liquids and liquid residues from both fire scenes and hands.