Methodology and Interpretation of Toxicological Procedures (From Medicolegal Investigation of Death, P 571-589, 1980, by Werner U Spitz and Russell S Fisher - See NCJ-69730)

• NCJ Number: 69745
• Author(s): J R Monforte
• Date Published: 1980
• Length: 19 pages
• Sale Source: Charles C. Thomas
• Language: English
• Country: United States of America
• Note: *This document is currently unavailable from NCJRS.

Annotation

Laboratory methods and associated instrumentation used in toxicological analysis, as presented in a forensic pathology text, are discussed; test selection as related to the sample substance is emphasized.

Abstract

In any analysis the procurement of a representative sample is the most critical step in the procedure. Blood is the sample that in most instances reflects the clinical condition of the individual. In addition, gastric contents, liver analysis, urine, lung, and spleen analysis may provide valuable information. Separation methods used in the laboratory remove drugs from a biological specimen such as blood, bile, urine, cerebrospinal fluid, vitreous humor, or tissue. Distillation methods are used for separating substances with low boiling points, such as alcohol. Microdiffusion, solvent extraction, and column chromatography are also used. After separation, the substance is analyzed. For many substances there exists more than one method of analysis. The choice of method depends upon the instrumentation available and the sensitivity, specificity, and precision required in the particular instance. The five primary methods of analysis include spectrophotometry, chromatographic methods, immunologic methods, gas chromatography-mass spectrometry, and special methods for metal analysis. Ultraviolet spectrophotometry is one of the most common methods employed for drug analysis. Other methods in this category include visible spectrophotometry and fluorometry. Chromatographic methods are basically separation methods, but they are also used for identification and in some cases, quantitation. Thin-layer chromatography and gas chromatography are examples of this type. Immunologic techniques are based on the binding of a specific labeled drug to an antibody. The analysis depends on the competitive displacement of the labeled drug from the antibody complex by the unlabeled drug in the sample. Gas chromatography-mass spectrometry is the most sophisticated analytical method currently available. Methods for metal analysis include atomic absorptions spectroscopy, anodic stripping voltammetry, and the Reinsch test. Seventeen references, sketches, tables, and a photograph are included. For related documents, see NCJ 69731-44 and 69746-47.