The process of removing dissolved gas from the mobile phase before or during use. Dissolved gas may come out of solution in the detector cell and cause baseline spikes and noise. Dissolved air can affect electrochemical detectors by reaction or fluorescence detectors by quenching. Degassing is carried out by: heating the solvent, by vacuum ( in a vacuum flask), on-line using evacuation of a tube made from a gas permeable substance such as PTFE, or by helium sparging.