Facilitated Hydrodynamic Sample Introduction into Separation Capillary in Laboratory Electrophoretic Devices

Abstract

A simple and fast method of pressure sample introduction of a sample into a separation capillary of electrophoretic device is described. Except manual exchange of the vessel with a separation buffer for that with a sample, the other sampling steps are computer-controlled. Without moving the capillary, the sample is introduced by pressure generated by a membrane pump and adjusted with a simple mechanical manostat applied to a vessel with the sample solution for a defined time period. The method was tested on separation of a 0.5 mM K⁺, Na⁺ and tyramine mixture. The results were compared with those obtained by a manual sampling utilizing an elevation of the capillary sampling end. Under the same sampling conditions, the results of both methods are quite comparable. The repeatability of the described method is better than that of the manual method. The same principle can be used for capillary washing or for its activation.