Can Phosphate buffer (25mM, pH 2.6) and AcN mix on line?
We try to convert the same HPLC method to UPLC method. It appeared mixing online gave the better resolution for 6 impurities in 4 mins. If we premixed the mobile phase (phosphate buffer pH 2.6 and AcN 75%:25%, isocratic), we have to extend our run to 4.5 min at least. Is that possible we mix phosphate buffer and AcN on line? I haven't had problem during the method development when I take caucious cleaning the buffer line.