PREP Symposia Series (Popularity: ): International symposium, exhibit and workshops on preparative/process chromatography, ion exchange, adsorption/desorption processes, and related techniques. Pittcon (Popularity: ): Annual Conference on Analytical Chemistry and Spectroscopy. Held each March, in a different city. Netherlands Catalysis and Chemistry Conference (Popularity: ): Held annually. Next meeting: Noordwijkerhout, The Netherlands; 10--12 March 2003.