The primary duty of the Toxicology Unit is to analyze blood and urine for the presence of impairing compounds in the investigation of driving under the influence charges. Blood samples are tested using headspace gas chromatography for alcohol content to determine whether the ethanol level exceeds legal limits. Liquid samples such as alcoholic beverages are also analyzed for alcohol content in order to aid the police investigations where the question of alcohol content is suspected. Both blood and urine are analyzed for the presence of performance impairing illegal and prescription drugs. Initially, samples are screened using an antigen antibody test to determine what class of compounds may be present. To conclusively identify a specific drug a variety of extraction techniques and instrumentation including gas chromatography mass spectrometry (GC/MS) are utilized.
Another facet of the Toxicology Unit involves the testing of blood, urine, and liquids for drug facilitated sexual assault cases (DFSA). These cases involve drug impaired victims and subsequent unsuspected sexual attack. The detection of trace amounts of impairing compounds including benzodiazepines and/or gamma hydroxy butyrate (GHB) can aid law enforcement in the investigation of these cases.