Basic analytical toxicology

Overview

The aim of this manual is to help hospital laboratories in developing countries to provide a basic analytical toxicology service using a minimum of special apparatus. It is not intended to replace standard texts, but to provide practical information on the analysis of a number of substances frequently involved in acute poisoning incidents. Common pitfalls and problems are emphasized throughout, and basic health and safety precautions for laboratory workers are also discussed. Problems encountered when using relatively simple methods in analytical toxicology are usually due to interference (false positives) or poor sensitivity (false negatives).

Nevertheless, useful information to help the clinician, and thus the patient, can often be obtained if the tests are applied with due caution using an appropriate sample. While every effort has been made to ensure that the tests described are reliable and accurate, no responsibility can be accepted by UNEP, !LO or WHO for the use made of the tests or of the results obtained. As in all areas of analytical chemistry, problems in interpretation can arise if a result is used for purposes for which it was not intended. This is especially true if the results of emergency toxicological analyses, particularly if poorly defined (for example, "negative drug screen", "opiates positive" ), are used as evidence in legal proceedings many months or even years later. In this context, the importance of consultation between the clinician treating the patient and the analyst in making best use of the analytical facilities available cannot be overemphasized. To assist this dialogue, some information on clinical interpretation has been included.