The influence of the concentration of cyclohexane radicals bonded with an Si100 silica gel surface upon the retention of some hydrocarbons in gas chromatography

Four adsorbents based on silica gel Si100 with chemically bonded cyclohexan e have been prepared as stationary phases for gas chromatography. The conce ntrations of cyclohexane radicals thus bonded with the silica gel surface w ere 1.35, 3.35, 4.17 and 6.02 mu mol/m(2), respectively. Separation of alip hatic (C-6-C-12), aromatic (benzene, toluene and m-xylene) and some polar o rganic compounds (chloroform, ethylene chloride, chlorobenzene, p-chlorotol uene and ethyl benzene) by gas chromatography using columns packed with the prepared adsorbents was studied. It was concluded that the retention of so me compounds was increased on the column packed with an adsorbent of 1.35 m u mol/m2 concentration relative to that measured on the column packed with the unmodified silica gel. On columns packed with adsorbents with a higher bonded phase concentration than 1.35 mu mol/m(2), the retention times of al l the compounds studied chromatographically decreased with an increase in t he bonded phase concentration.