<p>The purpose of this study was to evaluate enantioselective analytical methods by separation of the enantiomers of four drugs (citalopram, zopiclone, tramadol and methylphenidate) and their metabolites. The analyses were performed with HPLC-UV with columns whose stationary phases were based on macrocyclic glycopeptides (Chirobiotic V, V2 and T) and polysaccharides (Lux Cellulose-1, Cellulose-2 and Amylose-2).</p><p>The Chirobiotic V column showed high selectivity for citalopram and its metabolites. High resolution was obtained using a mobile phase consisting of methanol, acetic acid and ammonia. High selectivity for the enantiomers of zopiclone and its metabolites were obtained on the Cellulose-2 column using a mobile phase consisting of acetonitrile and ammonium acetate buffer.</p><p>The enantiomers of tramadol were separated with the Amylose-2 column. However, changes in the pressure arose, probably caused by the additive NH₄HCO₃. When the analysis was repeated at a later occasion, reproducible results were not obtained. With the Cellulose-1 column, lower selectivity was obtained, resulting in unacceptably long analysis time.</p><p>Only a few analyses of methylphenidate were performed and the results indicated that the glycopeptide columns had higher selectivity for this compound than the polysaccharides.</p>

The purpose of this study was to evaluate enantioselective analytical methods by separation of the enantiomers of four drugs (citalopram, zopiclone, tramadol and methylphenidate) and their metabolites. The analyses were performed with HPLC-UV with columns whose stationary phases were based on macrocyclic glycopeptides (Chirobiotic V, V2 and T) and polysaccharides (Lux Cellulose-1, Cellulose-2 and Amylose-2). The Chirobiotic V column showed high selectivity for citalopram and its metabolites. High resolution was obtained using a mobile phase consisting of methanol, acetic acid and ammonia. High selectivity for the enantiomers of zopiclone and its metabolites were obtained on the Cellulose-2 column using a mobile phase consisting of acetonitrile and ammonium acetate buffer. The enantiomers of tramadol were separated with the Amylose-2 column. However, changes in the pressure arose, probably caused by the additive NH4HCO3. When the analysis was repeated at a later occasion, reproducible results were not obtained. With the Cellulose-1 column, lower selectivity was obtained, resulting in unacceptably long analysis time. Only a few analyses of methylphenidate were performed and the results indicated that the glycopeptide columns had higher selectivity for this compound than the polysaccharides.