Evaluation of Internal Standards for the Analysis of Ignitable Liquids in Fire Debris

Abstract

An evaluation of eight compounds for use as an internal standard in fire debris analysis was conducted. Tests were conducted on tetrachloroethylene, chlorobenzene, n-octylbenzene, 3-phenyltolune, and deuterated compounds toluene-d8, styrene-d8, naphthalene-d8, and diphenyl-d10 to measure the extraction efficiency of each compound in the presence of an interfering volatile compound (carbon disulfide). Other tests were conducted to evaluate whether or not the presence of an ignitable liquid or pyrolysis/combustion products from fire debris would interfere with the identification of these compounds when used as an internal standard. The results showed that while any of the eight compounds could be used as an internal standard in fire debris analysis, the more volatile compounds (toluene-d8, tetrachloroethylene, chlorobenzene, and styrene-d8) showed better extraction efficiencies at room temperature than when heated to 60 degrees C. Each of the less volatile compounds (naphthalene-d8, diphenyl-d10, n-octylbenzene, and 3-phenyltolune) performed well during extraction at 60 degrees C, while naphthalene-d8 showed better extraction efficiency in the presence of competing volatiles when extracted at room temperature.

Application of Unsupervised Chemometric Analysis and Self-organizing Feature Map (SOFM) for the Classification of Lighter Fuels

“…The application and efficiency of using volatile chlorinated compound as the internal standard for fire debris analysis, such as Tetrachloroethylene has been reported. , A chlorinated compound was used mainly because it is not commonly encountered in ignitable liquid samples and is cost-effective and easily identifiable.…”

Preparation of Pyrolysis Reference Samples: Evaluation of a Standard Method Using a Tube Furnace

“…Another drawback to this method is that a relatively large sample must be burned/pryolyzed. It was while collecting pyrolysis data from different substrates in our laboratory using a muffle furnace (18) that we found that accurately controlling the time and temperature for different samples could not only give reproducible results, but also that the amount and type of pyrolysis products generated varied with time and temperature. As a result of this observation, and the desire to scale‐down the sample size, we turned our attention to the use of a steady‐state tube furnace.…”