*** 9531319 Ledford The chemical analysis of mixtures is commonly required in chemistry, materials science, biotechnology, and environmental science. If the application demands detection, identification, and quantification of more than a very few substances in a mixture, then chemical separation is usually required. Most current methods of separation are either very slow or are limited to only a small portion of the mixture. The objective of this proposed research is to develop much faster instrumentation for the chemical analysis of moderately complex mixtures. The method employs two independent chemical separations applied in series to a mixture in such a way that the whole sample passes through both separations generating a separation in two-dimensions rather than one. The second of the two separations operates so quickly that it can be applied repeatedly to each small portion of the mixture emerging from the first separation. This method, comprehensive two-dimensional gas chromatography, has been demonstrated in the research laboratory. This research project will develop a rugged instrument for commercial application. The instrument will detect, identify, and quantitate volatile organic substances in mixtures containing about one hundred components within five minutes or less. ***