In our lab we often use column backpressure as a measure of column life, i.e when the backpressure shoots up, the column needs some tlc (and may well be dead soon)

I have seen (probably in one of Mr Dolan's articles) a way to estimate column back pressure based on length, diameter and particle size, but can't rmemebr it for the life of me, anyone remember it ? (I've searched LC-GC - no luck)

Ta

Paul.