An environmental survey relating to improvised and emulsion/gel explosives

The detection and identification of traces of inorganic ions and sugars can play a major role in the forensic investigation of an explosives related i ncident. This survey investigated the background levels of these substances in the general environment. Six sampling locations were selected from arou nd the mainland of the United Kingdom, representing urban and rural sites. Swab and vacuum samples were collected from different locations within each site including motor vehicles, private houses, hotels, the exterior of bui ldings, road surfaces, and street signs. Sampling was carried out in summer and winter to investigate changes in the levels of the target species due to seasonal factors such as road treatments or weather. The samples were ex tracted with water and analyzed for a range of inorganic anions, cations, a nd sugars using ion chromatography. Most of the target anions were found to be common to all locations. Chloride, sulphate, nitrate, and phosphate wer e found to be the most common and the most abundant. Chlorate was found at a low level in some external samples. Perchlorate and thiocyanate were not detected in any samples. There was a marked increase in the quantity of sod ium and chloride detected in samples collected during the winter. Sodium an d calcium were detected in most samples. Potassium and magnesium were detec ted in approximately half of the samples. Ammonium was less common but dete cted at significant levels in wall samples. Glucose, fructose, and sucrose were detected in the vacuum samples from the interior surfaces of houses, h otels, and cars.