Zero Flow™ Capillaries by MicroSolv are designed to be Electro-Osmotic-Flow (EOF)-free. This is due to a covalently bonded inner coating that eliminates surface hydroxyl group activity responsible for bulk flow or EOF. Therefore it is normal to observe “no eluent” of buffer or any liquid even at high voltages. This can be beneficial because uncontrolled EOF is known to contribute to a lack of robustness in CE.
When conditioning the capillary, pressure may be used to push buffer through the capillary. In this case, you will see buffer coming out. If not, then there is likely a blockage in the capillary which is an issue so please contact our customer service department at email@example.com or call us 1-732-380-8900 between 9:00AM and 5:30PM EST.
Movement of the Cationic or Anionic analytes through the capillary from inlet to electrode is due to their electro mobility only and EOF is not involved.