Abstract
The work presents research results on separation and determination of three isomers: 1-N-o-(m- or p-)bromobenzyl-[5-(4′-morpholinyl)methyl]cytosines. The research included three stationary phases and three mobile phases: acetonitrile, methanol, mixture of acetonitrile/water/formic acid. When using octadecyl stationary phase considered to be standard as well as the octyl one, no separation of the aforementioned isomers of cytosine derivatives was observed, regardless of the mobile phase type. It was only when the chemically bonded aryl (naphthylpropyl) stationary phase was used that the separation of the aforementioned isomers was possible within 7 min. This phase was also characterized by the greatest selectivity (α = 1.90 and 1.53) of the cytosine derivatives being assayed, with the use of methanol as the mobile phase at 0.5 mL/min flow.