THE DETERMINATION OF THE HOMOLOGOUS PURITY OF HIGHER NORMAL-ALKANES UP TO DOHECTANE WITH CAPILLARY GAS-CHROMATOGRAPHY

The applicability of high-temperature capillary gas chromatography was tested for higher members of normal alkanes up to dohectane. The samp les used were synthesized and showed a high state of purity. The linea r relationships were proved between the logarithm of the retention tim e and the number of carbon atoms in the molecule, n, for the chromatog raphy at an isothermal operation. It was possible to detect the differ ence in n by one for octacontane samples. The homologous impurity was proved to be quantitatively determined by the chromatography under an isothermal operation or under a programmed-temperature operation for m ixtures of a limited range of n. The latter mode operation was desirab le to detect higher components as sharp peaks. Even for dohectane the high-temperature capillary gas chromatography could be applied for the purpose of purity determination.