Xbridge 2.5um, its brilliant.
<p><span>Has anyone else tried using alternative columns on the acquity systems rather than the 1.7um BEH? </span></p><p style="height: 8pt"/><p><span>We've found that the BEH (C18) columns void at or before 1500 injections using our predominantly high pH conditions due to dissolution of the stationary phase, which is a bit dissapointing with a 1.2minute runtime for a heavily used instrument, so we've been trailing a few different alternative phases to see if we can get better lifetimes.</span></p><p style="height: 8pt"/><p><span>So far most columns we have tried show directly comparable performance without changing any of our method conditions and most of these are running at significantly lower pressures than the BEH (around 5000 vs 8000psi). Up until recently the BEH was till lasting the longest, not any more....</span></p><p style="height: 8pt"/><p><span>The latest column we've put on the system is the Xbridge C18 2.5um and its worked so well I thought I'd share the news with anyone who's interested. This shows equivalent resolution to the BEH using our methods but so far its run around 5000 injections and its still looking really good!! Thats over 3 times the lifetime of the BEH column and we see no loss in performance whatsoever with our applications. Its running at around 4500psi so we're also thinking of transferring it to our regular HPLC systems to either get more resolution or cut our runtimes for these too!</span></p><p style="height: 8pt"/><p><span>We'll have to fiddle around with dimensions and flow rates in order to compensate for the difference in system volumes of an alliance vs an acquity system but we're looking at some potentially big cost savings due to cheaper columns that last longer, run faster and use less solvent!!</span></p><p style="height: 8pt"/><p><span>Why are Waters not marketing the 2.5um column more!!?? </span></p>