Chromatographic study of ketoprofen enantiomers adsorption on polysaccharide-based chiral adsorbent

Author: Aluda Tchelidze
Keywords: Enantiomers, Thermodynamic parameters, enthalpy, entropy
Annotation:

The goal of our research was the calculation of thermodynamic parameters of enantioseparation in high-performance liquid chromatography. This can help to predict the suitable analytical conditions for the given compound on given column and to achieve the desired selectivity and enantiomer elution order. For the experiment several weakly acidic compound were chosen, particularly arylpropionic acid derivatives, which are nonsteroidal anti-inflammatory drugs (NSIDs). They are used as painkillers and antipyretics. It is important to separate their stereoisomers, as frequently only one enantiomer has pharmacological activity and the other one is inactive or even toxic. In this thesis only the behavior of one chiral substance-Ketoprofen is described in detail. Also we compared thermodynamic parameters using amylose tris(3,5-dimethylphenyl carbamate), cellulose tris(3,5-dimethylphenyl carbamate) and cellulose tris(3-chloro-4-methylphenyl carbamate) coated on silica gel as stationary phases. Analyses were performed at various temperatures. For analyzed compounds, the values of adsorption enthalpy and adsorption entropy betveen enantiomers were calculated using the plot of natural logarithm of the separation factor versus the reciprocal of the absolute temperature. The goal was to evaluate wether the enantioseparation was controlled by enthalpic or entropic term and what was the influence of temperature on retention and separation. The results of this study have shown temperature significantly affects chiral recognition pattern of polysaccharide phenylcarbamates. The question is if the change of chiral recognition pattern is caused by any chemical or structural change in the chiral selector, chiral analyte, both of them or, it is the result of enthalpy-entropy compensation. In order to get some idea on this regard, the enantioseparation of ketoprofen was studied on Lux Amylose-1 column in the temperature range 10-60°C when increasing the column temperature with 5° increments and afterwards, when cooling of the same column with the same increments down to 10°C.

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კეტოპროფენის ენანტიომერების ადსორბციის ქრომატოგრაფიული კვლევა პოლისაქარიდული ბუნების ზოგიერთ ქირალურ ადსორბენტზე [ka]