Electrophoresis in nanometer inner diameter capillaries with electrochemical detection.

Separations have been achieved in 770- and 430-nm-inner diameter capillaries. The extremely low sample volumes involved in the study of biological microenvironments such as single cells has led to the desire to develop separation techniques in these ultrasmall capillaries. Total sample volumes as low as 12 fL have been injected using these nanometer inner diameter capillaries. Separations of several catecholamines have been accomplished in these submicrometer capillaries using both capillary zone electrophoresis and micellar electrokinetic chromatography with end-column amperometric detection.