Analysis of 3-quinuclidinol derivatives by capillary electrophoresis

Capillary electrophoresis with indirect UV detection was applied to the analysis of a mixture of 3-quinuclidinol and its four quaternary derivatives (N-methyl, N-ethyl, N-propyl, and N-isopropyl derivative). 10 mM imidazole acetate buffer, pH = 4.0 offers suitable detection sensitivity (LOD = 1 mumol L-1) and permits separation of the mixture except for the pair 3-quinuclidinol- N-methyl derivative. The separation of all analytes was achieved on addition of 15 mmol L-1 beta-cyclodextrin or 25% (w/w) polyethylene glycol 2000 to the background electrolyte. The optimized method was employed for the analysis of pond water spiked with these analytes. Actual ionic mobilities of the studied compounds were measured using mobility standards (potassium, sodium, tetramethyl- and tetrabutylammonium). The migration index was derived as another identification parameter based on migration data and the precision of the obtained values is discussed in brief.