Capillary electrophoresis‐inductively coupled plasma‐mass spectrometry: A report on technical principles and problem solutions, potential, and limitations of this technology as well as on examples of application

Abstract

This paper summarizes some basic principles of capillary electrophoresis (CE), inductively coupled plasma-mass spectrometry (ICP-MS), and coupling of both devices. Especially the interfacing is described in detail. A special focus is drawn to various interface developments reported in literature and technical problems, i.e., requirements to the interface setup and respective solutions. Nowadays, typically sheath flow-based interfaces are used. The sheath flow fulfills two requirements of hyphenation, (i) the closing of the electrical circuit of CE and (ii) the feeding of the used nebulizer with an adequate flow rate. In the beginning of CE-ICP-MS coupling predominantly home-made interface-nebulizer constructions were developed and tested for various speciation problems. Now increasingly such laboratory-constructed interfaces are left. Mostly commercial nebulizers are employed being combined with commercially available tee or cross fittings to connect the CE capillary to the electrode, the additional sheath flow, and the nebulizer. Due to the low sample amounts and low flow rates from CE, such nebulizers are typically low-flow nebulizers like, e.g., the microconcentric nebulizer (MCN) and the direct injection nebulizer (DIN). However, there are also reports on couplings using standard Meinhard systems. Still the control and reduction of a siphoning sucting flow and sufficient detection limits are the major problems in hyphenating CE to ICP-MS. Different solutions are reported on these problems and summarized here. Finally numerous applications are reported. Mostly, applications are performed on speciation of selenium, arsenic, metallothionein isoforms, mercury, or cobalt.

Efficient Interface for Online Coupling of Capillary Electrophoresis with Inductively Coupled Plasma–Mass Spectrometry and Its Application in Simultaneous Speciation Analysis of Arsenic and Selenium

“…32,33 In this work, a miniaturized DIHEN chamber was designed and used for ICP-MS in order to minimize the gas phase dead volume and maintain the high resolution of CE. The sprayer was fit on this homemade chamber as showed in Figure 1.…”

Capillary electrophoresis hyphenated to inductively coupled plasma‐mass spectrometry: A novel approach for the analysis of anticancer metallodrugs in human serum and plasma

“…Recently the focus has shifted towards mass spectrometric detection such as ESI-MS [25,26] and inductively coupled plasma (ICP)-MS [27][28][29][30], opening new possibilities for the characterization of metallodrug interactions with biological targets [7,31]. Especially ICP-MS, the unrivalled detector in terms of specificity and LOD of metals bound to biomolecules, seems best-suited for quantification of adducts, especially if only present in traces [32,33].…”

Speciation of organotin compounds in environmental samples with semi-permanent coated capillaries by capillary electrophoresis coupled with inductively coupled plasma mass spectrometry

“…Self-aspiration of the sheath flow liquid can minimize or eliminate the laminar flow completely. 22 Nitric acid was proved to be the best choice as the make up solution, which can avoid potential disadvantages such as plasma instability, poor precision, and degradation of ICP-MS performance.…”