Feasibility of Enhancing High-Performance Liquid Chromatography Using Microwave Radiation

Abstract

High-performance liquid chromatography (HPLC) is the most versatile of the chromatographic techniques because it is applicable to a wide variety of analytes. Unfortunately, liquid mobile phases have relatively low diffusivities. A novel approach is presented for increasing the diffusivity of a liquid mobile phase. The method advocated in this study is the first process that has been described by which it is possible to increase the diffusivity of a liquid while having essentially no effect on other physical properties of the liquid, such as the temperature or solvating power. It is demonstrated that it is possible to sharpen peaks, in an HPLC separation, by the application of microwave radiation.

Influence of Microwave Irradiation on the Mass-Transfer Kinetics of Propylbenzene in Reversed-Phase Liquid Chromatography

“…This increase in the intraparticle diffusion of propylbenzene is probably affected by the molecular excitation of the organic modifier, which has a higher dielectric loss than the studied solute. Our results are in agreement with the recent qualitative findings of Stone and Taylor …”

“…Our results are in agreement with the recent qualitative findings of Stone and Taylor. 40 However, the mode of action of the microwaves in the diffusion of the solute molecules inside the column remains unclear at this time.…”

Microwave assisted high performance liquid chromatography for the separation of triacylglycerols in vegetable oils using an evaporative light scattering detector

“…This phenomenon could promote the dispersion of the peaks (Jerby, 2017). The presence of a solvent in the mobile phase with a low boiling point and a high loss factor could partially account for this behaviour that was not observed in other studies before where the mobile phase did not contain volatile solvents , (Stone & Taylor, 2003). Consequently, even though a lower apparent separation efficiency could be found with MW-HPLC with respect to conventional heating at 40 ºC, it was better than room temperature (25-26 ºC) and still similar to that obtained at 30ºC, with the advantage that the retention times were shorter.…”

“…Recently, microwave assisted HPLC (MW-HPLC) has emerged as a possiblen alternative 5 separation method to those in which the column temperature is controlled by means of a 6 conventional oven , 7 Galinada & Guiochon, 2007;Stone & Taylor, 2003). The 8 microwave heating mechanism is based on molecule dipole rotation and ionic migration processes.…”

“…Until now there are few primary studies highlighting the possibilitiesbenefits of using microwave irradiation to perform the separation of organic species because of the combined effect of mobile phase heating and a possible influence of the microwave radiation on the analyte partition equilibrium between the two chromatographic phases (W. A. Stone & Taylor, 2003;Turner, Laurence, Conner, & Yngvesson, 2000) . The first studies revealed an enhancement of chromatographic efficiency when microwave radiation was applied compared with the use of conventional heating (i.e., based on a conduction-convection mechanism).…”