A specialized electrophoretic apparatus in a "H-configuration" has been designed for separations in short capillaries with lengths of a few cm. The sample injection and the capillary rinsing are designed so that the separation capillary position is unchanged.
The sample injector consists of an electronically-controlled 6-way injection valve, a piezoelectric micropump and a delivery tube in which the separation capillary inlet is fixed. The sample is injected without interruption of the separation voltage.
The capillary rinsing is provided by a membrane pump generating underpressure at the end vial. The apparatus is equipped with a contactless conductometric detector.
All the operations and the data acquisition are controlled by a computer.