A chromatographic system that includes a light source and an imaging and analysis system for detecting particle size and analyzing other characteristics of particles in the effluent of a filtration column while filtration is ongoing. The effluent is directed into a guiding tube having a flow axis. Coherent light from the light source is shone into the guiding tube along the flow axis, thereby illuminating particles in the effluent within the guiding tube. An imaging device is used to capture images of the portion of the light scattered by the particles. The image signals are analyzed and used to provide information regarding particle size and other characteristics of the particles in the effluent scattering the light.