EFFECT OF CO-MODIFIERS IN CYCLODEXTRIN-MODIFIED MOBILE PHASES ON THE REVERSED-PHASE HIGH-PERFORMANCE LIQUID CHROMATOGRAPHIC SEPARATION OF POLYAROMATIC HYDROCARBONS

摘要

The effect of two co-modifier containing tert.-butyl moieties, tert.-butyl (N-hydroxy) carbamate and tert.-butyl carbazate, on the retention behavior of six polyaromatic hydrocarbons (PAHs) using cyclodextrin-modified mobile phases has been examined. Both modifiers resulted in shorter retention times for all PAHs, when a size-compatible cyclodextrin was present in the eluent. This decrease has been attributed to the formation of a ternary PAH-cyclodextrin-modifier complex. The apparent formation constants calculated for these complexes are of the order of approximately 10(2) M(-1), with the exception of the beta-CD-pyrene complex, which was determined to have a 2:1 stoichiometry. Mixtures of beta- and gamma-cyclodextrins were used in the mobile phase along with tert.-butyl carbazate to achieve a baseline separation of all six PAHs under 50 min. [References: 13]