In this book, the proceedings of the Third European Symposium on Analysis of Organic Micropollutants in Water , held in Oslo (Norway), from 19 to 21 September 1983, are presented. The symposium was organized within the framework of the Concerted Ac- tion COST 64b bis *, which has the same name and is included in the Third R&D Programme on Environment of the Commission of the European Communi- ties - Indirect and Concerted Actions - 1981 to 1985. The aim of the symposium was to review the progress and results achiev- ed during the past two years, since the Second symposium, held in Killarney (Ireland) in November 1981. The programme of the symposium consisted of review papers covering dif- ferent areas related to the analysis of the organic pollutants in water, in- cluding sampling and sample treatment, gas and liquid chromatography, mass spectrometry and specific analytical problems for some types of compounds. We think that the volume gives a rather complete overview of these activities in Europe. Moreover, the paper presented by D. Hunt reviews the development of the new technique mass spectrometry - mass spectrometry in the United States of America. Some special sessions concerned the presentation of original contri- butions in form of poster, the extended versions of which are published in this volume.