Comparison of local anesthetic-cyclodextrin non-covalent complexes using capillary electrophoresis and electrospray ionization mass spectrometry.

Non-covalent complexes between three derivitized cyclodextrins (CD's) and six local anesthetics were studied using capillary electrophoresis (CE) and electrospray ionization mass spectrometry (ESI-MS). The CE study was performed using the complete filling technique (CFT). A comparison between the migration data from CE and ESI-MS inclusion complex peak abundances was made representing the association between local anesthetics and CD's in the solution and the gas phase, respectively. The results from this study showed comparable behavior of the complexes in the CE and mass spectrometer, indicating similarity in the parameters controlling the stability of these complexes. Therefore, the formation of specific non-covalent complexes, as shown in this study, could be used to predict the behavior of a complexing agent with a substrate in the solution phase by observing data obtained from ESI-MS.