It is easy to make a water plug injection. Firstly, you should only put the water plug after the sample or in other words, then make a post injection water plug. Depending on you capillary size, you should make inject the CEwater for 1 second at 0.5 psi. If the capillary is a 75m, you can inject the CEwater for 10 seconds at 0.1 psi. Be sure to make both your sample and your CEwater injection toward the cathodic buffer and not to “waste” or an empty vial. Use a ramping time of 1 minute.