What purpose does sparging serve?

Some gases, like oxygen, nitrogen and carbon dioxide, have a tendency to dissolve into solution at a much greater rate than do inert gases such as helium. Even though they do have a higher solubility in most solvents, they often do not have equal solubility in all solvents.

What does this mean to visible quality performance of your equipment? If you are running an isocratic method, pulling your pre-mixed solvent from one reservoir only, then it probably doesn’t mean much in reduced performance. However, if you are running any method that pulls solvents from multiple reservoirs, it can result in the formation of bubbles in your solvent line.

One very helpful way to keep the amount of dissolved gas in your solvents very low is through sparging. The sparging process forces an inert — and virtually insoluble — gas into a solution, driving out dissolved gases from the solvent. This helps prevent the formation of bubbles in your flow stream, helping to produce better chromatographic results.