Cross-correlation capillary electrophoresis in unmodified commercial equipment

The present contribution deals with the use of unmodified commercial equipment for cross-correlation capillary electrophoresis (CE). Complex injection sequences have been injected by switching sample and background electrolyte vials according to a preprogrammed order. Because of the nature of the auto-sampler used, no sequence could be injected in commercial instrument without high voltage (HV) interruptions. Apparently, this is the main reason why obtained signal-to-noise (S/N) ratios are lower than theoretical. Specific ways of programming the injection sequence and use of modified injection sequence in the correlation process have been used to overcome the deleterious effect caused by this sample injection. An electro-osmotic flow (EOF) marker was used as a sample to find optimal conditions for cross-correlation experiments. Best results demonstrate S/N ratio improvements around 2.8 compared to 4.0 theoretical maximum.