New techniques that improve the portability, selectivity, sensitivity, and economy of drug assays are important to the mission of the National Institute on Drug Abuse (NIDA). Recent advances in electrochemical detectors and dector arrays, portable instrument design, and applied artificial intelligence are combined in the proposed work. The result is a low-cost, portable, and highly selective liquid chromatograph for the qualitative and quantitative analysis of drugs in body fluids. In this Phase I SBIR research, an apparatus is assembled and tested in order to evaluate the feasibility of portable LCEC system that has exceptional analytical capabilities. The resultant device will have a microcomputer and software to allow automated analyses and make the equipment easy to use.