The invention relates to liquid chromatography techniques for rapidly characterizing samples, such as polymer solutions, emulsions and dispersions, and to devices for implementing such techniques. The system includes a design that provides the ability to perform chromatographic separations by using mobile phase composition gradients and temperature gradients during separations. The invention accomplishes this by providing mixing zones for a plurality of fluids as well as heated and chilled feeds feeding the fluids to the mixing zones. Additionally, the system provides the ability to analyze separated components with a detector and/or collect separated fractions into vessels of a fraction collector for further separation and/or analysis.