High Performance (High Pressure) Layer Electrochromatography Separation Technique: Equipment and Preliminary Results

Abstract

We present a new prototype device and propose a new analytical technique: high performance (high pressure) layer electrochromatography (HPLEC). The equipment provides a combination of overpressured layer chromatography (OPLC) and pressurized planar electrochromatography (PPEC), yet it still enables researchers to perform each of these analyses separately. In comparison to PPEC, HPLEC provides hydrodynamic flow of the mobile phase, irrespective of the voltage used and the mobile phase composition. The advantages of HPLEC over OPLC include the possibility of the use of the electrophoretic effect to influence the selectivity of separation and the use of the electroosmotic effect to facilitate the mobile phase flow in order to decrease backpressure and increase the flow velocity. Many operational parameters can be freely adjusted and optimized independently. The equipment is fully automated and can work in various separation/operational modes, including combinations of online/offline sample application and detection. We present preliminary results of simultaneous, fully online, multichannel HPLEC separation of analgesic drugs (including acetaminophen, ibuprofen, and tramadol) as an example of increasing analysis throughput.

Comparison of Overpressured-Layer Chromatography and High-Performance/High-Pressure Layer Electrochromatography Using the New Prototype Equipment in Various Operational Modes

“…This suggests that the flow profile of the mobile phase through the adsorbent layer is smooth and uniform. This was confirmed by the multichannel test of the sample application and the detection described in our previous paper [1].…”

“…In the paper mentioned above, we have shown an exemplary HPLEC analysis of simple (two-component) analgesic drugs mixtures-Metafen and Poltram Combo Forte solutions [1]. Here, we present a comparison of OPLC (Figure 2a) and HPLEC (Figure 2b,c) of more complex dye mixture in similar separation systems.…”

“…The mobile phase composition and properties can be optimized (e.g., pH, polarity) to obtain required retention, without paying attention to their influence on electroosmosis. This presents many possibilities to optimize various HPLEC parameters to obtain the best results expected, as discussed elsewhere [1].…”

“…In our previous paper [1], we have presented the new prototype equipment for the new analytical technique-high-performance/high-pressure layer electrochromatography (HPLEC). The technique is a combination of overpressured-layer chromatography (OPLC) and pressurized planar electrochromatography (PPEC).…”

“…The HPLEC equipment was designed to work in various operational modes, concerning the number of samples analyzed simultaneously, the mobile phase flow ratio: flow from the main pump vs. flow from the sample pump, and the sample application and detection mode (online, offline, or their combination). In our previous paper, we have shown only some very preliminary results concerning the fully online and fully automated, simultaneous, multichannel HPLEC separation of analgesic drugs in a reversed-phase system [1]. The others operational modes were not investigated yet.…”