Dear all,I have some problems with my system pressure and I don't know the reason. I have a very high delta pressure. My conditions: flow=0.05 mL/min, A1=ACN100%, B2=ACN70%, A1/B2=50/50, system pressure=3608psi, delta=589 (see attach). Column ACQUITY UPLC BEH C18 1.7 um, 2.1x150 mm and guard column C18 1.7um. Thank you.