Report, the editors replaced the term "speciation" wherever it occurred by "identification and quantification," or "description of abundance," or "reactivity," or "transformation" of a chemical species, according to whichever one of the four meanings the author had evidently meant to convey. In line with the Dahlem Workshop Model, this Report comprises the background papers written in advance of the meeting on the current status of problems in environmental research and on advanced analytical tech niques for the identification and quantification of chemical species, as well as the group reports summarizing the results of the discussions held during the meeting. Each group report was prepared during the meeting by one "rapporteur" with the help of members of that group and finalized by the rapporteur (listed as the first author of the group report) after the meeting, taking into account both verbal comments made during the presentation of the reports in the plenary session at the end of the workshop and written comments received afterwards."

Biological chemistry is a major frontier of inorganic chemistry. Three special volumes devoted to Metal Sites in Proteins and Models address the questions: how unusual ("entatic") are metal sites in metalloproteins and metalloenzymes compared to those in small coordination complexes? and if they are special, how do polypeptide chains and co-factors control this? The chapters deal with iron, with metal centres acting as Lewis acids, metals in phosphate enzymes, with vanadium, and with the wide variety of transition metal ions which act as redox centres. They illustrate in particular how the combined armoury of genetics and structure determination at the molecular level are providing unprecedented new tools for molecular engineering.

Biological chemistry is a major frontier of inorganic chemistry. Three special volumes devoted to Metal Sites in Proteins and Models address the questions: how unusual ("entatic") are metal sites in metalloproteins and metalloenzymes compared to those in small coordination complexes? And if they are special, how do polypeptide chains and co-factors control this? The chapters deal with iron, with metal centres acting as Lewis acids, metals in phosphate enzymes, with vanadium, and with the wide variety of transition metal ions which act as redox centres. They illustrate in particular how the combined armoury of genetics and structure determination at the molecular level are providing unprecedented new tools for molecular engineering.