Differences In Partition Coefficients Research Articles

A reversed-phase partition chromatogram using chlorinated rubber.

UNTIL quite recently, the substances used for supporting the stationary phase in partition chromatography have held the more polar solvent preferentially. Chromatograms of this type have been very satisfactory for the separation of substances with predominantly water-soluble character; but several workers have pointed out that full advantage cannot be taken of small differences in partition coefficients if these are in the range which gives R values1 much above 0.5. In the case of compounds such as the higher fatty acids, where the partition coefficients greatly favour the non-aqueous phase, these ideal conditions cannot be realized, and it has been suggested that a system in which the phases are reversed would lead to useful results. Attempts have been made by Boscott2, using cellulose acetate, and by Boldingh3, using rubber powder, to hold the less polar phase on the inert support, and recently Howard and Martin4 have described the use of kieselguhr, impregnated with silane, for a reversed-phase partition column.

Anesthetic Properties of Procaine Amide (Pronestyl) and Other Amide Analogues of Local Anesthetic Compounds.

Conclusions1. The anesthetic potencies of three anesthetics and their amide analogues have been determined and compared.2. The amide analogues are relatively ineffective as anesthetics upon intact nerve trunks.3. The partition coefficients between Ringer's solution and chloroform and between buffered isotonic saline of these anesthetics and their amide analogues have been determined.4. The differences in partition coefficients between these anesthetics and their amide analogues and their pharmacological actions have been discussed.

Application of the Paper Partition Chromatogram to the Qualitative Analysis of Reducing Sugars

GORDON, MARTIN AND SYNGE1 and Consden, Gordon and Martin2 have shown that good separations of amino-acids can be obtained on filter paper by allowing a suitable solvent, which has previously been saturated with water, to flow over the paper in a closed container, the air in which is saturated with the vapours of water and the solvent. Filter paper contains 20–25 per cent water under these conditions, and separation depends upon the differences in partition coefficient of the amino-acids between the stationary water phase and the moving solvent. It has further been shown2 that for any individual amino-acid the value