How to evacuate a glass vessel containing powders? I would like to evacuate a vessel (a glass round-bottomed flask) and which contains a few grams of platinum. However, I am worried about the platinum powder being sucked up by the vacuum.

A few people told me that this is possible if I take some care, but I am still not convinced. I use a turbo pump in combination with a diaphragm pump for the rough vacuum. So in the end a very expensive vacuum cleaner! I know that the powder will destroy the turbo pump if the powder is sucked in. Do any of you have some experience with powders in vacuum?
I often high-vac powders on Schlenk. Issues only arise when going between positive and negative pressures though to minimise any risk I often lightly plug the sidearm of the glass stopper/adapter(?) with cotton wool. Glass wool would also suffice and I am certain there are already stoppers/adapters which have a porous mesh build in to prevent powder from entering the vacuum system.