| 摘要 |
PURPOSE:To inject a sample in a capillary only by electroosmotic flow while suppressing electrophoresis by a method wherein the end of the capillary on the injection side of the sample is covered with a conductive member to be dipped in the sample and the conductive member is used as one electrode. CONSTITUTION:A collar 8 is preliminarily attached to the tip of a capillary 2 on the injection side of a sample and the capillary 2 and the collar 8 are filled with a buffer solution and the collar 8 is connected to the anode of a high voltage power supply 4 to be dipped in the sample 10. The cathode end of the capillary 2 and a cathode 14 are dipped in the buffer solution 12. When migration voltage is applied across both ends of the capillary 2 in this state, the sample is injected in an electrophoretic manner. In this case, since the collar 8 provided at the end of the capillary 2 on the injection side of the sample acts as an electrode, the electric field of the sample solution around the collar 8 becomes uniform. Therefore, no electrophoresis is generated in the sample sucked by electroosmotic flow over the range up to the tip of the capillary. By this method, electrophoresis is suppressed and the sample can be injected in the capillary only by electroosmotic flow. |
