The University of Washington, Department of Chemistry requests funds for the purchase of a quadrupole low resolution mass spectrometer with GC and direct inlet and a FAB probe. This instrument will replace an aging and ailing GC-MS instrument and will serve a core user group of ten faculty members in the departments of chemistry and Medicinal Chemistry. Major projects to be served by the proposed instrument are (1) Molecular Pharmacology (2) Drug Interactions with Valproic Acid. (3) Synthesis and Study of Theoretically Interesting Molecules (4) Bioorganic and Natural Products Chemistry (5) Rational Design of Enzyme Inhibitors (6) Organic and Bioorganic Chemistry (7) The Metabolism of Compounds that Form Reactive Intermediates (8) Studies on Drug Metabolism and Receptor-Binding Agents (9) Total Synthesis of Natural Products and (10) Mechanisms of Drug Interactions and Drug Metabolism.