Gas chromatographic studies of derivatives of celluline-like substances.
Abstract Different aspects of the gas chromatographic determination of the celluline-like substances exhibiting specific cardiotonic activity are discussed. As this substances is isolated from frog skin and bladder, many impurities have to be considered. Determination of these samples, having a broad range of boiling points, was performed by means of programmed-temperature gas chromatography. Identification of unknown peaks was executed with the help of pure standard substances and retention indices.
Contribution to the theory of the retention index system
Abstract After examining the relationship between retention index and column temperature under isothermal conditions, we have shown in a recent publication that the temperature-dependence of the retention index may generally be determined by an Antoine-type equation: After further investigation, we have established that the retention indices can be exactly calculated from programmed-temperature gas chromatography data with the following equation: A great advantage of this equation is that the data from normal hydrocarbons are not included in it.
Gas-liquid chromatography in qualitative analysis : Part VII. The role of the support in gas chromatographic retention measurements
Abstract The support phase has been shown to influence values for relative retention by either the adsorption of solute moleculs or the adsorption of the hydroxyl groups of certain polar liquid phases. Also, it has been deduced that appropriately shaped molecules, which have a low affinity for the solvent, can be selectively retained by trapping in the micro pores in the surface of certain supports, in particular teflon. On the basis of these observations it has been found that silanized Chromosorb G is the least adsorptive of a wide range of commercially available support materials.