by Steve Down
One of the tasks of fire investigators is to try to identify the types of materials that have been burned, which is not all that easy when all you have left is charred debris. In theory, the residues can be analysed and the results compared with those held in a library but the nature of fires is so variable that comparisons are difficult. Fires can burn in different amounts of oxygen and at different temperatures, and materials can also be destroyed by heating in the absence of air, a process known as pyrolysis.
In the forensic world, the definition of pyrolysis has been extended to mean thermal degradation at any temperature in the presence of any amount of oxygen, so the process of creating reproducible pyrolysis libraries of reference substances is especially difficult. However, these problems may have been solved by a scientist working at Trace Evidence Services at the National Centre for Forensic Services, Royal Canadian Mounted Police, Edmonton, Canada.
Source: Separations Now