Chemical databases: an overview of selected databases and evaluation methods

Scientific information is more and more buried in the proliferation of commercial sites on the Internet. This means that valuable chemistry sites and chemical databases are difficult to find. In this paper some databases selected by the authors are introduced. These sites can be divided into three groups: databases which used to be only available through commercial hosts; databases which are available commercially but parts of them on the free Internet; and databases of topical concern, e.g. chemical weapons. All the mentioned databases can be found in a structured format in the DAIN Metadatabase of Internet Resources for Environmental Chemicals, which is explained in this paper. An important further step to get out of the information labyrinth is the evaluation of the content of data-sources for chemicals. Approaches have been made to analyze chemical databases applying discrete mathematical methods and multivariate statistics.