High-throughput development of catalysts, initiators, and polymeric materials combines automated parallel catalyst synthesis and automated polymerization reactors. The reactors can be additionally equipped with on-line monitoring (ReactIR from Mettler) based on ATR-FT-IR technique. This powerful tool has proven to be a very valuable probe for high-throughput experiments. During copolymerizations of ethene and 1-hexene monomers, the ReactIR was used to monitor the 1-hexene conversion as well as polymer formation, polymer concentration, and polymer composition. This gives access to information on catalyst activity, activation and deactivation times of the catalyst, polymerization kinetics, copolymerization parameters, and the degree of homogeneity of the resulting copolymers. The technology is especially useful for solution copolymerization. The spectrometer can be applied in the lab as well as in Pilot plants and production facilities where rapid on-line analyses are useful for product quality control. (C) 2003 Elsevier Ltd. All rights reserved.