Studies on column size scale-up and flow profile in conical shape liquid chromatographic column of 10? by visualization method

Abstract

An improved visualization device made of polymethyl methacrylate (PMMA) was used to study the 3D flow profile inside conical columns of a 10º opening angle packed with C₁₈ phase. The outside wall of the conical columns was rectangular in shape in order to improve the transparency property of the column wall and reduce the deformation of the image for better observation of the flow profiles of colored solutes inside the column. The influence of flow rate, particle size and shape on the flow profile of a colored band were studied on a 5-cm-long column and a scaled-up column of four fold in volume. It was found that the flow rates of the mobile phase had little influence on the flat flow profile of the iodine band while the properties of the stationary phase had a certain influence on them. We observed that the flow profiles of the scaled-up column were flat during the whole chromatographic process, and the efficiency and resolution of the column were also increased in accordance with theoretical prediction. The experimental results proved that the 10º conical columns can be proportionally scaled up while still keeping the flat flow profile, sample load per unit volume of packing material, and column efficiency, which are superior to the conventional column.