Toxicology and Accident Research Laboratory for the Federal Aviation Administration Quality Control/Assurance (QC/QA)
Quality Control/Assurance (QC/QA)
Quality Control/Assurance is a key element of the Toxicology and Accident Research Laboratory. Specimens received are carefully inventoried to account for every piece of evidence received from an aviation accident. Detailed reports are prepared to account for every drop of sample used from a case. All batches submitted for analysis contain a blind positive control and a blind negative control to monitor test results. Analysts are not allowed in the accessioning area and do not know the identity of the aliquots given to them for analysis. Only the accessioning staff and the reviewing official have access to the identity of the specimens being analyzed.
A complete chain of custody is maintained to account for the specimens in the laboratory and the aliquots being tested. The chain of custody forms are dated and signed by everyone who handles the specimens or the paper work. All reports leaving the laboratory are reviewed by three staff members before the reports are signed by the manager of the laboratory and mailed to the agency requesting the tests. Specimens from positive cases are stored for five years and negative cases are stored for two years. This allows for independent testing by an outside laboratory if there are questions regarding the test results.
A national proficiency testing program is also administered and maintained by the toxicology laboratory. Proficiency testing samples for drug analysis are prepared in biological fluids and tissue and distributed to the participating laboratories quarterly. Analytical results from the participants are summarized, reviewed, and distributed to them for their self-evaluation. This unique program allows the participants to evaluate their professional development and technical currency on an interlaboratory basis and to assess their methods in the presence and absence of postmortem interfering substances.
Analysis of specimens is conducted using state of the art equipment. Screening for abused drugs is performed by Fluorescence Polarization Immunoassay (FPIA) in urine and by Radioimmunoassay (RIA) in blood and tissue. Prescription and over the counter drugs such as cardiovascular agents, tranquilizers, antihistamines, and decongestents are screened by High Performance Liquid Chromatography (HPLC), Gas Chromatography Mass Spectroscopy (GC/MS), Enzyme-Linked Immunosorbent Assay (ELISA), and FPIA. Drugs are confirmed and quantitated using GC/MS, Gas Chromatography Infrared Spectroscopy (GC/FTIR), and by HPLC Mass Spectroscopy. Alcohol is screened and confirmed by Head Space Gas Chromatography and by FPIA. Carbon Monoxide and Cyanide are screened and confirmed by UV/Vis Spectroscopy.
Research is performed using the most advanced equipment available in the world. The laboratory is capable of and has identified substances never reported in the literature. The laboratory can take an unknown substance found in a pilot's blood and determine the identity of the substance by using Gas Chromatograhy Atomic Emission Detection to determine the elemental composition of the compound, Gas Chromatography Infrared Spectroscopy to identify the molecular functional groups, GC Chemical Ionization Mass Spectroscopy to identify the molecular weight of the compound, and by GC Electron Ionization Mass Spectorscopy to identify the molecular fragments of the compound.