Peak capacity in gradient ultra performance liquid chromatography (UPLC)

A prototype commercial instrument and 2.1 mm i.d. columns packed with 1.7 mu m porous particles have been used to measure peak capacity in ultra performance liquid chromatography (UPLC). Peak capacity was measured for a small molecule pharmaceutical as a function of gradient time, mobile phase flow rate, and column length. For very fast analysis, the highest peak capacity is obtained from a short column operating at high linear velocities. If an even higher peak capacity is required, a longer analysis time must be employed, and a point is reached where switching to a longer column becomes the best approach. (c) 2005 Elsevier B.V. All rights reserved.