Chromatography Forum

I am wondering whether it's still damaging the bonded PEG capillary column when injecting aqueous sample into it, 'cos as far as I know this kind of column is prone to water and oxygen.

All depends upon "how much" (how much water, how much oxygen, how much heat, how much time at that temperature). We've made 0.5 ul water injections for over a decade on a PEG column (Supelco Nukol) for alcohol assays at 40C with no issues. Prior to a sequence we take up to 150C.

Air is more damaging to a bonded phase wax column that water is. As long as you keep the system airtight you can do a lot of water injections without damaging the column. The column might last longer if you don't do water injections, but the difference wouldn 't be significant. Remember, a column is considered a consumable item, they aren't designed to last forever.