Trouble Shooting Common Injection Problems

Some of the most common problems with HPCE is caused by problems or errors created during the injection procedure. Following is a short table of Problems and Causes and Solutions to these problems.

Problem	Cause/Solution
No Injection at all	Replace the capillary or unplug the capillary Check the pressure or vacuum of the system Check to see if your sample vial is empty Check to see if you are injecting from the correct vial Check your polarity. Make sure it is set properly Call your instrument's service technician to check the injector
Variable Current	Large Injection causes this normally — reduce the amount you are injecting Plugged Capillary? It should be replaced Check to see if you are using the correct buffer vial You may have injected an air bubble. Recondition the capillary Check to make sure that the anolyte and the catholyte are the same, at the same level and electrolysis did not take place due to buffer depletion
Poor Peak Area	Inject more sample in subsequent runs Check to make sure that electrolysis did not occur due to buffer depletion. If so, replace the anolyte and the catholyte Check to make sure that there is sufficient sample in your injection vial. Watch out for evaporation as well