Spiral tube assembly for countercurrent chromatography

现有的用于高速逆流色谱的两相溶剂系统涵盖了疏水性至中等极性溶剂系统的分离，但通常不能为高极性化合物如磺酸染料、儿茶酚胺和Twitter离子提供合适的分配系数值。 本文介绍了一种新的溶剂系列，可用于螺旋管逆流色谱分离这些极性化合物。 它由正丁醇、乙醇、饱和硫酸铵和水按不同体积比组成。该系统由10个步骤组成，这些步骤根据溶剂系统的极性排列，使得可以在几个搜索步骤中找到具有适合目标化合物的K值的两相溶剂系统。 每种溶剂系统在两相之间提供适当的体积比和高密度差，并在螺旋柱组件中提供令人满意的固定相保留水平。 通过对4种典型极性化合物（碱性染料甲基绿色、磺基染料柠檬黄、酪氨酸和肾上腺素）在正丁醇-水体系中的分配系数测定，验证了该方法的有效性。最近，通过在20个步骤（1至10和11至20）中增加溶剂组成，已经改进了上述超极性溶剂体系（有机/高离子强度水性溶剂体系）。使用这种新系统，两相系统的图解测定可以分两步完成，即，首先在系统10中对样品进行分区。 如果K值大于1，则在系统1处执行第二K确定，而如果系统1中的K值小于1，则在系统20处执行第二K确定。 通过在这两点之间画一条线，在每种情况下，从与K = 1的线的交点可以容易地获得接近1的最佳K值。该方法成功地应用于柠檬黄（K=0.77）、色氨酸（K=1.00）、甲基绿色（K= 0.93）、酪氨酸（K= 0.81）、间苯二酚（K=0.89）、酪胺（K=0.98）和去甲间苯二酚（K=0.96）的分离。 采用两相溶剂系统图解选择法，对D&C绿色8号中的三种磺酸组分进行了高速逆流色谱分离，并将其应用于极性化合物（碱基、核苷、核苷酸）的分离。

Existing two-phase solvent systems for high-speed countercurrent chromatography cover the separation of hydrophobic to moderately polar solvent systems, but often fails to provides a suitable partition coefficient values for highly polar compounds such as sulfonic dyes, catecholamines and twitter ions. The present paper introduces a new solvent series which can be applied for separation of these polar compounds by spiral tube countercurrent chromatography. It is composed of 1-butanol, ethanol, saturated ammonium sulfate and water at various volume ratios. The system consists of 10 steps which are arranged according to the polarity of the solvent system so that the two-phase solvent system with suitable K values for the target compound(s)can be found in few steps of search. Each solvent system gives proper volume ratio and high density difference between the two phases, and provides a satisfactory level of retention of the stationary phase in the spiral column assembly. The method is validated by partition coefficient measurement of four typical polar compounds including methyl green (basic dye), tartazine (sulfonic dye), tyrosine (twitter ion) and epinephrine (catecholamine), all of which show low partition coefficient values in the polar 1-butanol-water system. Recently, the above ultra polar solvent systems (Organic/high ionic strength aqueous solvent system) has been improved by increasing the solvent composition in 20 steps (1 to 10 and 11 to 20). Using this new system, a graphic determination of two-phase systems can be done in two steps, i.e., first the sample is partitioned in system 10. If the K value is over 1, the second K determination is performed at system 1 whereas if the K value in system 1 is below unity, the second K determination is performed at system 20. By drawing the line between these two points, the optimum K value of near unity can be easily obtained from the crossing point with the K = 1 line in each case. The method was successfully applied to separation of tartrazine (K=0.77), tryptophan (K=1.00), methyl green (K= 0.93), tyrosine (0.81), metanephrine (K=0.89), tyramine (K=0.98), and normetanephrine (K=0.96). Three sulfonic acid components in D&C Green No. 8 were separated by HSCCC using the graphic selection of the two-phase solvent system This new method was also applied for separation of ultra polar samples polar compounds including nucleobases, nucleosides and nucleotides.