Apparatus for Pressurized Planar Electrochromatography in a Completely Closed System

Abstract

Pressurized planar electrochromatography (PPEC) is the mode which offers much higher separation efficiency in comparison to conventional planar chromatography, including both higher performance and much higher speed of separation. In this paper, we present a new device for performing PPEC in which the whole area of the chromatographic plate is pressurized. Both electrodes (anode and cathode) are washed with the mobile phase during the experiment, which prevents gas bubbles from collection in the region of the electrodes. This device enables directly controlling the flow rate of the mobile phase during the electrochromatography process. Mobile phase control offers the possibility of researching the influence of various properties of the PPEC system on separation efficiency. One important relationship to investigate is plate height vs mobile phase flow rate. This relationship helps to choose the optimal value of the mobile phase flow rate during the separation process. Considerable difference in shape of this relationship is demonstrated for conventional planar chromatography plates and high performance planar chromatography plates. Examples of the influence of some properties of the separating system on flow rate of the mobile phase are demonstrated, such as the buffer concentration in the mobile phase, the pH value of the buffer solution of the mobile phase, the type of chromatographic plate, and the voltage applied to the electrodes.

High performance stationary phases for planar chromatography

“…Electroosmosis is used to drive the mobile phase flow through the layer in pressurized planar electrochromatography and requires an aqueous buffer as a component of the mobile phase [23,[57][58][59][60][61][62]]. An electric field applied across the layer is used to control the mobile phase velocity which is independent of the solvent front migration distance.…”

Planar Electrochromatography in a Closed System under Pressure—Pressurized Planar Electrochromatography

“…[19] Other devices for PPEC were designed by our group. [15,16] Our first construction for PPEC was based on a commercially available horizontal DS chamber for TLC. [15] The next device was a quite new construction which is schematically presented in Figure 3.…”

“…[15] The next device was a quite new construction which is schematically presented in Figure 3. [16] A prewetted chromatographic plate with the adsorbent layer face down is horizontally positioned in the chamber and is completely covered by a teflon foil and silicon sheet, which are pressed to the adsorbent layer by plastic and metal blocks. Special troughs beneath the adsorbent layer situated on both sides of the chromatographic plate are used for mobile phase delivery to the chromatographic plate.…”

“…Electrodes, anode on the left side and cathode on the right side of the chromatographic plate in Figure 3, are situated in channels for mobile phase solution and are washed with the mobile phase during the electrochromatography process. More detailed description of the device is presented in the reference [16]. An important feature of the equipment is control of the flow rate of the mobile phase.…”

Microchip free flow planar reversed phase electrochromatography with monolithic stationary phase

“…Recently, Nurok [6] and Dzido et al [7] made comprehensive reviews on recent progress of PEC, which demonstrated its advantages of improved resolution and efficiency compared to conventional planar chromatography. Although good separation of dyes was obtained in RP PEC mode [5], the excessive evaporation of mobile phase in open surrounding and the accumulation of solutes on stationary phase resulted in poor reproducibility.…”