Numerical modeling of capillary electrophoresis - electrospray mass spectrometry interface design

Abstract

CapillaryQ3 electrophoresis hyphenated with electrospray mass spectrometry (CE-ESI-MS) has emerged in the past decade as one of the most powerful bioanalytical techniques. As the sensitivity and efficiency of new CE-ESI-MS interface designs are continuously improving, numerical modeling can play important role during their development. In this review, different aspects of computer modeling and simulation of CE-ESI-MS interfaces are comprehensively discussed. Relevant essentials of hydrodynamics as well as state-of-the-art modeling techniques are critically evaluated. Sheath liquid-, sheathless-, and liquidjunction interfaces are reviewed from the viewpoint of multidisciplinary numerical modeling along with details of single and multiphase models together with electric field mediated flows, electrohydrodynamics, and free fluid-surface methods. Practical examples are given to help non-specialists to understand the basic principles and applications. Finally, alternative approaches like air amplifiers are also included.

Recent advances in CE‐MS coupling: Instrumentation, methodology, and applications

“…The detailed description of electrical potential distribution and analyte transfer within common CE‐ESI‐MS designs was brilliantly reviewed by Jarvas et al. . Besides the sample dilution given by interface construction, the efficiency of analyte transfer into MS has much higher impact on the sensitivity of CE‐ESI‐MS analyses.…”

“…Recently developed low flow interface questioned a broadly accepted opinion, that sheathliquid significantly dilutes the sample and is a cause of significantly lower sensitivity. The detailed description of electrical potential distribution and analyte transfer within common CE-ESI-MS designs was brilliantly reviewed by Jarvas et al [33]. Besides the sample dilution given by interface construction, the efficiency of analyte transfer into MS has much higher impact on the sensitivity of CE-ESI-MS analyses.…”

Simulation‐based design of a microfabricated pneumatic electrospray nebulizer

“…The nitrogen entered the nebulizer channels at 6 bar and 293 K. Under these conditions of channels the gas exited the chip at a very high velocity, dragging the analyte from the edge of the nearby separation channel. Unfortunately, the commercially available and even the custom‐made software packages cannot adequately resolve numerically the droplet formation (by defining the mesh resolution, the minimum droplet diameter is determined), therefore, numerical simulations carried out focusing only on the gas phase. The calculations were done in 2D mirror symmetric mode in order to reduce the computational demand.…”

Effect of the flow profile on separation efficiency in pressure‐assisted reversed‐polarity capillary zone electrophoresis of anions: Simulation and experimental evaluation

“…Connection of CE to MS by an ESI interface represents a promising combination to obtain good separation efficiency and detection versatility . CE–ESI‐MS hyphenation can be typically accomplished by means of three different interface types: co‐axial sheath–liquid interface, sheathless interface, and the so‐called liquid–junction interface . The most frequently used is the sheath–liquid interface .…”