Gas chromatography/mass spectrometry is the best method for identification of unknown compounds in environmental samples. The most convenient technique for identification is a use of library search system. But commercially available search system and data base of mass spectra have several disadvantage such as wrong spectra or insufficient search algorism. Therefore, a new library search system has been developed in this study. In this part of our report, studies performed in the Okayama Prefectural Institute for Environmental Science and Public Health are described. Furthermore, a new technology has been established for correction of mass spectra which are significantly different from mass spectra in data base because of difference of instruments used and operational conditions. Evaluation of the new system in actual environmental analysis and crosscheck were performed and satisfactory results were obtained.
