It's not so much about how long you pump, it's a matter of completing cycles until it stops bubbling. Look at degassing methods for spectroscopic lifetimes in papers. You might need to degas for 3 cycles or 10 cycles. It's solvent-dependent and if you backfill with an inert atmosphere. I would need to FPT water 10-15 times to get a steady lifetime. Chloroform, 3 or 4. Does your vacuum pump have a gauge on it? That should reach a minimum and steady value.
It's not so much about how long you pump, it's a matter of completing cycles until it stops bubbling. Look at degassing methods for spectroscopic lifetimes in papers. You might need to degas for 3 cycles or 10 cycles. It's solvent-dependent and if you backfill with an inert atmosphere. I would need to FPT water 10-15 times to get a steady lifetime. Chloroform, 3 or 4. Does your vacuum pump have a gauge on it? That should reach a minimum and steady value.More
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