Effect of alcohol chain length, concentration and polarity on separations in high-performance liquid chromatography using bonded cyclodextrin columns

✍ Scribed by Ibrahim Z. Atamna; Gary M. Muschik; Haleem J. Issaq

• Publisher: Elsevier Science
• Year: 1990
• Tongue: English
• Weight: 783 KB
• Volume: 499
• Category: Article
• ISSN: 1873-3778
• DOI: 10.1016/s0021-9673(00)96994-2

✦ Synopsis

The effect of alcohol chain length, concentration and polarity on separation in high-performance liquid chromatography using /&cyclodextrin-bonded silica is discussed. The results show that retention times cannot be predicted merely from the polarity of the binary mobile phase. Although organic modifiers with the same physice-chemical properties and from the same solvent group were used, the retention times obtained using binary mobile phases having the same polarity, were different. It was also observed that normal-chain carbon alcohols gave retention times shorter than those obtained with a branched-chain alcohol (n-propanol vs. isopropanol), and the longer the alcohol chain the shorter the retention times. A plot of In k' vs. alcohol volume fraction for benzene, toluene, ethylbenzene, propylbenzene, butylbenzene, I-phenylhexane and I-phenyloctane gave a linear relationship in methanol, ethanol and propanol (except for 1-phenylhexane).

A non-linear relationship was obtained for all the solutes in isopropanol, tert.-butanol and 1-butanol, in the alcohol volume fraction studied.