The effect of the concentration of the ionic liquid didecyldimethylammonium lactate on the retention and separation of pyrimidine bases

Ionic liquids (IL) are new materials with a wide spectrum of use. Being a variable combination of an organic cation and an organic or inorganic anion, their have controllable properties. The effect of the ionic liquid added to the mobile phase on the separation of uracil derivatives is studied and demonstrated in this paper. The ionic liquid used was didecyldimethylammonium lactate, which has an advantageous effect on the separation of the analytes studied. Pyrimidine bases which were used as the test compounds are characterized by alkaline properties due to which so-called peak tailing is observed during separation. A methanol/water mixture was used as the mobile phase in the chromatographic analyses. Optimum separations were obtained for 8% levels of the organic modifier. The best separations of the test isomers were obtained for 0.01% IL added to the mobile phase. The findings obtained are evidence that the use of ionic liquids in HPLC is an efficient method for the separation of polar compounds: the duration of the analysis is shorter and the resulting peaks are sharp and symmetrical.