This project will replace an obsolete mass spectrometer with a computer- controlled gas chromatograph/mass selective detector for use by undergraduate students in organic chemistry, chemical instrumentation, applied analyses, and spectrometric and separation methods. The mass selective detector, associated computer hardware and software acquired for this project will be interfaced with a gas chromatograph recently donated to the chemistry department, thus providing GC/MS capability. Principles and techniques to be taught in upgraded or new experiments include operation of a computer-controlled GC/MS; identification of a sample compound from the relative magnitudes of the P, P+1, and P+2 peaks; separation and identification of compounds in complex mixtures; and identification of compounds by interpretation of fragmentation patterns.