Pressure drop in liquid chromatography

Abstract

Measurement of pressure drop is routinely performed during chromatographic runs. In many cases this information is only used for regulation of mobile phase flow rate to keep pressure drop below defined limit. However, pressure drop can provide additional important information about performance of chromatographic process. In this review different parameters affecting pressure drop such as compressibility of chromatographic media, nature of applied sample and mobile phase flow regime are discussed. Detailed analysis correlating organization of particle based chromatographic media and pressure drop is presented together with its extension to convective media such as membranes and monoliths but also novel 3D printed media. Finally, estimation of layer thickness formed by adsorbed molecules based on a pressure drop data is presented and its applicability is discussed.

Evaluation of the van Deemter equation in terms of open‐ended flow to chromatography

“…The result obtained with the parameter values in Table 1 is v x (max) = (0.19 ± 0.10) m/s. Equation 9 shows that the velocity of the overall-peak maximum (v x (max)) depends on L 0 , x 0 , and the velocities that characterize the flow, turbulence effects [10,44], and packing of the column.…”

“…14a, Tables 1 and 2, Figure 7). It has a magnitude of approximately 10 µm (Table 2), and it can be interpreted as the effective size of the grains or pores of the stationary phase that constitutes the column [10]. The constant "B" of Eq.…”

“…Band broadening [7], or an increase in the full-width at half-maximum (FWHM) of the peaks, may be induced by adsorbed or nonadsorbed solute molecules, where the latter corresponds to convection or diffusion mechanisms [8]. During flow, both mobile phase [8] and solute molecules [9] may be trapped within pores of the stationary phase [10]. It is still debated whether adsorption theory [11,12], partition theory [1,3,13,14], or combinations thereof [15] should be used to model chromatographic peaks; nevertheless, all of these theories [16][17][18] give rise to Gaussian peak shapes.…”

Tubular Catalytic Polyhipe Reactor with Deposited Silver Nanoplate Nanoparticles

“…The matrix microstructure plays an important role in maintaining a high matrix permeability after catalyst loading. While the deposited catalyst inevitably decreases the porosity, the change in pore size should be as small as possible to avoid a substantial decrease in permeability [16]. With this in mind, high internal phase emulsion polymer (poly-HIPE) monoliths seem to be a good choice.…”

Macrocyclic glycopeptide‐based chiral selectors for enantioseparation in sub/supercritical fluid chromatography

“…Decreased pressure drops and back pressure lead to reduction of frictional heating and enable the use of such stationary phases at higher flow rates without losing efficiency 50 . Plate heights of columns produced with SPPs are less dependent on the mobile phase (MP) flow rate compared to FPPs, hence they are better suited for high speed separations 52,57,62,63 …”