[Handling of biological material before trace element determination].

The various steps of the analytical process are taken into account with particular reference to problems arising in sampling biological materials, their storage, pretreatment, digestion (when necessary) and determination. Emphasis is laid on the fact that the availability of analytical equipment with exceptional detection power is not always flanked by an equivalent ability to control phenomena of contamination and/or loss of analytes as well as to check and guarantee the accuracy of experimental data. In this context, proper use of the most popular analytical techniques for the determination of trace elements and the adoption of strict procedural conditions for data reliability are briefly discussed.