Liquid Chromatograph(y) or LC
Degassers are overwhelmingly underestimated as causing issues with instruments and chromatography. Vacuum, helium sparging, heat and also sonication are all valid methods of degassing, but I’m going to focus on vacuum degassing from the instrument itself.
Did you know the majority of instrument degassing units are not engineered to be the primary degassing solution? OEMs often suggest sonicating or degassing your solvents prior to placing them on the system. Take some time to read the degasser manual for further information.
Note: While helium sparging has been the most efficient form of degassing, helium has become far too expensive for most labs to perform. Heated sonication is probably the next best option.
Improper/inefficient degassing can cause many issue. As young lab techs, I’m sure everyone that has run an LC has encountered a bubble in their solvent stream at least once. This can cause the pump to lose prime, along with many other chromatography issues. But their are a few lesser known issues improper degassing can create.
Changes in solvent atmospheric content over time can cause retention time shifts of later eluting components. It can also create wandering baselines over times, as well. If you running gradients, the affects can be compounded.
Do not underestimate the value of your degasser or its limitations in degassing your solvents.