Effect of column efficiency on separation of organic compounds in vapor-phase chromatography

Abstract

Comparative analysis on the efficiency of separation of sequence of organic compounds via chromatography specifying the height equivalent to the theoretical plates has been carried out. Alongside with inert gas (nitrogen), water steam has been used as a mobile phase as well. It is shown that in the zones of low speed of mobile phase, the column efficiency slightly depends on the nature of applied carrier. Using water steam as a mobile phase instead of nitrogen in high speed allows increasing separation efficiency for 1.2-1.8 times. Moreover, the best results are observed when water steam is used. The symmetry of chromatographic zones with usage of mentioned mobile phases has been estimated as well. To confirm this, developed mixture (hexane, methyletylketone, benzol and chloroform) has been analyzed on “Triethylenglycol” polar fluid phase and on “Squalane” non-polar fluid. It was defined that when using water steam as mobile phases, the symmetry of chromatographic peaks dramatically improves, which promotes more precise separation of analyzed samples. The results of studies carried out allow concluding that when substituting non-polar mobile carrier-nitrogen for water steam, the column efficiency increases and separation improves as well.