A practical approach for predicting retention time shifts due to pressure and temperature gradients in ultra-high-pressure liquid chromatography

A multiscale modelling study on the sense and nonsense of thermal conductivity enhancement of liquid chromatography packings and other potential solutions for viscous heating effects

“…Since the temperature difference between the inside of the column and the environment is smaller at the start of the column, the radial temperature gradients are the smallest at the inlet and increase towards the end of the column. This is again similar to the situation observed at lower pressures [6,7,19,[21][22][23] .…”

“…7 shows the results obtained at 2500bar for the three different considered thermal boundary conditions. In general, the temperature contour plots are very similar to the ones already obtained in literature at lower pressures [6,7,19,[21][22][23] . They display similar shape, but higher absolute temperature values.…”

“…Similar to what is already well-documented for lower operating pressures [6,7,19,[21][22][23] , the isothermal lines in a column operated at 2500 bar still substantially run in the axial direction when the column is operated in a thermostatted environment (Fig. 7a).…”

Ultra high performance liquid chromatography method development for separation of omeprazole and related substances on core‐shell columns using a Quality by Design approach

“…It has been observed that, in reversed phase LC, pressure influences retention, selectivity, and efficiency. This has been shown to be true specifically for the separation of omeprazole and H 168/66 and is something that should be taken into consideration if changing chromatographic equipment.…”

“…Consequently, there is a possibility for this method to be transferred from UHPLC to HPLC, which might be necessary since not all laboratories have access to UHPLC equipment. However, one should be aware that a change in pressure might create a shift in elution order at different pH levels than what is seen in these experiments . Furthermore, the method still requires validation to verify these predictions and make sure all performance criteria are met.…”