Forensic toxicologists in the police laboratories and forensic medicine departments of university measure a variety of volatile substances in the course of investigating accidents, crimes, and other incidents. Blood alcohol (ethanol) is measured to provide evidence in cases of traffic accidents caused by drinking, incidents involving alcohol such as physical assault and injury, and acute alcohol poisoning. Paint thinner is a solvent with toluene, methanol, and ethyl acetate as its main constituents. Paint thinner also has anesthetic and stimulant properties. Paint thinner abuse by inhalation has become prevalent and laws have been enacted to prevent the harmful effects of its abuse. Used in industrial applications, cyanide and azide are compounds that are relatively easy to procure. This has resulted in incidents of contamination by these toxic substances. After these incidents, testing regimes for poisons were enhanced in order to determine the cause of such incidents, i.e. crime or suicide. Blood alcohol and paint thinner can be measured relatively simply using headspace sampler, with measurements performed on a routine basis at police laboratories and in university forensic departments. There have been reports of the headspace method being used to measure cyanide and azide. These compounds are normally measured by performing PFB derivatization, solvent extraction, and then liquid injection for GC/MS analysis. However, the derivatization and extraction steps of this method are labor-intensive.
This two-part application presents details on the investigation of using headspace GC/MS to measure cyanide and azide, as well as information on optimizing column conditions to allow simultaneous measurement of alcohol and paint thinner. Of these two investigations, results obtained from measuring blood alcohol and paint thinner are presented below. Please see Application Data Sheet No. 140 for part two.