Analytical Methods Used In Toxicology

ANALYTICAL METHODS USED IN TOXICOLOGY

Toxicology laboratories use several methods to screen for poisons/drugs, since there is no single, accurate, inexpensive method for this purpose. Each method differs in cost, accu-racy, complexity, speed, and specificity. The actual equipment required depends on the size of the laboratory and the kind of testing done. A basic, ideal laboratory should have the following facilities/resources:

·            Calibrated laboratory balances

·            Bench top centrifuge

·            Vortex mixer

·            Water bath and heating block

·            Butane gas burner

·            Fume cupboard

·            Refrigerator and Freezer

·            pH metre

·            Automatic/semi-automatic pipettes

·            Low power polarising microscope

·            Thin layer chromatography (TLC) plates

·            UV spectrophotometer

·            UV lamp

·            Conway microdiffusion apparatus

·            Porcelain spotting tile

·            Modified Gutzeit apparatus.

·              In addition, it is desirable to have the following specialised equipment, though they are quite expensive:

·      High Performance Liquid Chromatography (HPLC)*

·      Gas Chromatography (GC)

·      Mass Spectrometry (MS)

·      Facility for Radio Immuno Assay (RIA)

·      Enzyme Mediated Immuno Assay Technique (EMIT)**.

·      There should also be access to sophisticated systems of analysis which are normally beyond the scope of a toxicology laboratory, such as Atomic Absorption Spectrophotometry (AAS), and Neutron Activation Analysis (NAA).

In a given case of poisoning it may be sufficient to know just the nature of poison (qualitative analysis), or there may be a need for identification as well as estimation of its concentration in the body (quantitative analysis).