Polyethylene glycol as a separation medium for capillary zone electrophoretic analysis of pyridine derivatives

The influence of the addition of polyethylene glycol (PEG) to the background electrolyte on the capillary zone electrophoretic (CZE) separation of alkylpyridines was studied. It was found out that interactions between polyethylene glycol chains and protonized pyridine bases cause the increasing of the resolution. The separation of a model mixture of pyridine, all isomers of methylpyridine, and some other alkyl and aryl derivatives was performed. The separation was complete except for some dimethylpyridines. The influence of the co-ion was discussed, too. Polyethylene glycol solution as a separation medium was used for the capillary zone electrophoretic determination of pyridine bases in an industrial mixture. (C) 1999 Elsevier Science B.V. All rights reserved.