Continuous liquid chromatograph and its application to separation of natural organic compounds.

点击翻译按钮获取中文摘要

The need for a process which will separate mixtures such as natural substances and synthetic compounds continuously has long been felt, both in laboratory and in industry, because the widely-used batch chromatographic techniques are time-consuming and inefficient in their use of the column packing material. The principle of continuous chromatographic separation was first presented by Martin. However development of continuous liquid phase chromatography has been insufficient.A radial-flow disk chromatograph was designed and constructed in this research for the continuous separation of mixtures. In this apparatus, the space for the chromatographic packing materials is formed between the upper flat glass disk and the lower stainless steel disk. The bed of the fixed phase is, therefore,in the shape of the disk (2 mm thick, 270 mm diameter). The disk assembly is rotated by two variable-speed motors. The chromatographic disk was made by packing with silica gel-ODS under a centrifugal-force field at 1200 rpm. The continuous separation of a mixture of di-2-ethylhexyl phthalate and dibutyl phthalate was achieved using this packed disk, at feed-rate of 60 mg/h for each component under rotation at 2 rph, with methanol-water (19:1) mixture as eluent at flow-rate of 8 ml/min. The continuous separation of the phthalates was also performed on the silica gel disk at feed-rate of 180 mg/h for each component with a mixed solvent of hexane and ethyl acetate. The continuous chromatography of the mixture of amino acids, phenylalanine and tryptophan on a hydrophilic polyvinyl gel eluting with water gave satisfactory separation of the mixture to their components. The continuous liquid chromatograph having a rotating radial-flow disk has been proved to be valuable for the preparative separation of mixtures,so far studied.