This project is concerned primarily with new instrumental approaches for quantitative chemical determinations; principal emphasis is on three aspects of the total analytical process, namely sample processing, measurement, and data processing. The sample processing approach given principal attention to date has been stopped-flow mixing that permits reactions with half-lives as short as 20 ms to as long as many seconds to be monitored. Attention is being expanded to include centrifugal and flow-injection (f.i.) sample processing systems, with principal emphasis being adaptation of unique detector systems described below to these systems and a better understanding of the f.i. systems. Detector systems of greatest current interest are imaging detectors (vidicons, photodiode arrays, image dissectors) that permit large regions of the UV/visible region to be scanned with repetition rates as fast as 250 scans per second. These detectors are being used both for unique types of determinations involving molecular absorption and luminescence and atomic absorption and emission as well as fundamental studies of reactions involved in these determinations. Data processing studies are designed to use the multiwavelengtth data for multicomponent determinations, for error detection, and for most effective extraction of quantitative information from kinetic data. Resulting methodologies are expected to be applicable to most types of species including organics, enzymes, and trace elements, although the trace element work is being phased out of this project to permit time for better focus on organic and biochemical species.