CONICET | Buscador de Institutos y Recursos Humanos

The analysis of enantiomeric purity demands highly selective and sensitive analytical methods, able to detect traces (< 0.1%) of an enantiomer in the other one. The objective of this work is the development of systems that involve cyclodextrins derivatives (CDs) as quiral selectors in gas chromatography. The possibility that cyclodextrins and their multiple derivatives have (1) to form inclusion complexes with a wide variety of solutes of different chemical nature has been widely explored in order to develop numerous analytic methodologies. In this study, capillary columns were built by uniform deposit of the solutions of the derived octakis-(2,6-di-O-pentyl-3-O-butyryl)-γ-cyclodextrin in the 14% cyanopropylphenyl methylpolysiloxane (OV-1701) inside the walls of capillary fused-silica of 250 µm of internal diameter. It was used a construction system designed in our laboratory (2) that allows to know the quantity of deposited liquid with a high accuracy and, in consequence, the phase ratios of the prepared columns can be exactly estimated. The chromatographic characteristics of these columns are evaluated in connection with the efficiency, retentive capacity and, fundamentally, their capacity of enantioresolution of selected analytes from preliminary information obtained on a commercial similar column (LIPODEX-E). During the development of this work the density of the stationary phases developed was determined by picnometry in a range of temperatures of 50ºC to 100ºC. This allowed us to calculate the phase ratio corresponding to each column and all the temperatures. From the chromatographic retention times and dead times for the resolved enantiomeric pairs, along with the phase ratio at each temperature, preliminary calculations of the partition constant (K) associated to the enantioseparation process will be discussed.