Yes—using argon in the bottle’s headspace can help slow oxidation and may extend the life of stored photo chemicals, much like reducing air space with floating lids or accordion bottles. Argon is inert, so in that respect it is suitable.

However, it is not a complete solution. Oxygen is already dissolved in the liquid, so simply replacing the air above the solution will not remove that dissolved oxygen. Because of that, the benefit is limited: it can help, but it won’t stop chemical aging entirely.

A practical takeaway is that minimizing headspace is useful, but the best way to preserve chemistry is often to avoid mixing it until you need it. Even with an inert gas blanket, stored solutions will still age over time.