Compounds enriched in the rare isotopes of light elements, such as (18)O, (17)O, (13)C or (15)N, are used in a very large variety of isotopic tracing studies including investigating the microscopic mechanisms of the movements of atoms in solids. Owing to their very high cost or limited availability these products must be handled in gram amounts or less. Handling such compounds in small quantities in the liquid or gaseous state, purifying and recovering them for further use require special techniques that are described in detail in this paper. Dedicated vacuum lines are used for labelled water, special high vacuum furnace installations are required for thermal treatments with labelled gases that must be used under static conditions while remaining pure. Ion beam analysis is systematically used to investigate the wide spectrum of applications of isotopic tracing in electrochemistry and in applied physics. A number of typical experiments are outlined briefly providing examples for future experimental development in this field. (c) 2007 Elsevier B.V. All rights reserved.