Glossary of Terms in Forensic Toxicology

Absolute Method A method in which characterization is based on physically defined (absolute) standards. Accreditation (l) A formal process by which a laboratory is evaluated, with respect to established criteria, for its competence to perform a specified kind(s) of measurement(s); (2) the decision based upon such a process; (3) formal recognition that a testing laboratory is competent to carry out specific tests or specific types of tests. Accuracy Closeness of the agreement between the result of a measurement and a true value of the measured quantity. Acetaldehyde The first product of ethanol metabolism. Acute Severe, usually crucial, often dangerous in which relatively rapid changes are occurring. An acute exposure runs a comparatively short course. Acute tolerance The development of tolerance within the course of a single exposure to a drug. Alcohol dehydrogenase (ADH) The main enzyme that catalyzes the conversion of ethanol to acetaldehyde. Aldehyde dehydrogenase (ALDH) The enzyme that converts acetaldehyde to acetate. Aliquot (1) A divisor that does not divide a sample into a number of equal parts without leaving a remainder; (2) a sample resulting from such a divisor. Analyte The specific component measured in a chemical analysis. Analytical run (series) A set of measurements carried out successively by one analyst using the same measuring system, at the same location, under the same conditions, and during the same short period of time. Analytical sensitivity The ability of a method or instrument to discriminate between samples having different concentrations or containing different amounts of the analyte. Slope of the analytical calibration function. Analytical specificity Ability of a measurement procedure to determine solely the measurable quantity (desired substance) it purports to measure and not others. Analytical wavelength Any wavelength at which an absorbance measurement is made for the purpose of the determination of a constituent of a sample. Antemortem Before death, occurring before death. Ascites An abnormal accumulation of fluid in the peritoneal cavity of the abdomen. Assignable cause A cause believed to be responsible for an identifiable change in precision or accuracy of a measurement process. Beer’s law The absorbance of a homogeneous sample containing an absorbing substance is directly proportional to the concentration of the absorbing substance. 54511_book.fm Page 131 Friday, August 31, 2007 1:57 PM