Recent developments in coupled SPE‐CE

Abstract

This article presents an overview of coupled SPE-CE systems that have been reported in the literature between April 2007 and June 2009. The use of in-line and on-line SPE-CE is covered in this review. Special attention is paid to the use of monoliths and molecularly imprinted polymers in coupled SPE-CE systems. Application-oriented research is discussed in which in-line and on-line SPE-CE systems have been used in biomedical, pharmaceutical, environmental and food analysis. The SPE-CE studies are presented in tables, including information on sample type, SPE sorbent, detection and LOD. Finally, some future developments that may increase the applicability of coupled SPE-CE are highlighted.

In-line Solid-phase Extraction–Capillary Zone Electrophoresis for the Determination of Barbiturate Drugs in Human Urine

“…[1][2][3] Among them, solid-phase extraction (SPE) coupled to CE is a very promising technique because low limits of detection (LODs) can be achieved due to the high sample volume that can be injected. [3][4][5][6][7][8] SPE can mainly be performed in four different setups: off-line, on-line, at-line and in-line. The latter three of these setups have been of particular interest due to an increasing trend towards fully automated analytical methods; among them, in-line coupling on SPE and CE is the most widely reported at present.…”

“…The latter three of these setups have been of particular interest due to an increasing trend towards fully automated analytical methods; among them, in-line coupling on SPE and CE is the most widely reported at present. [3][4][5][6]9 In this setup, the preconcentration column is an integrated part of the CE system, and presents several advantages, such as a low volume of the organic solvent needed, easy automation, low requirement of sorbent material for constructing the SPE device, and its capability to analyze the complete eluate from SPE by CE. 3,4,7,10 Barbiturate drugs are typical sedative-hypnotic drugs and, depending on the substituting groups, exhibit a wide variety of responses in the body.…”

A Miniaturized Transverse Flow Gating Interface for the On-line Coupling of Solid-phase Extraction with Capillary Electrophoresis

“…Additionally, as the SPE column is physically separated from the CE capillary in the on-line system, this allows for independent operation and optimization of the SPE and the CE. [2][3][4][5][6] On-line coupling of SPE with CE requires a specially designed interface. In addition to implementation of electric connection for CE, the interface should have the ability to exactly transfer nanoliters of fractions from SPE onto CE with minimized degradation of the efficiencies of SPE and CE.…”

Bubble cell for magnetic bead trapping in capillary electrophoresis

“…Alternative strategies consist in preconcentrating the analyte before CE separation, either by electrophoretic stacking or by solid-phase extraction (SPE) [3][4][5]. In stacking methods, the volume of the sample must be lower than the total capillary volume [6]. In SPE, a large sample volume can be pumped to extract the target analyte by adsorption on the column, followed by elution with a small liquid volume yielding high preconcentration factors [6].…”

“…In stacking methods, the volume of the sample must be lower than the total capillary volume [6]. In SPE, a large sample volume can be pumped to extract the target analyte by adsorption on the column, followed by elution with a small liquid volume yielding high preconcentration factors [6]. For in-line SPE, the extraction column can take various forms, such as an open-tubular capillary coated with the SPE sorbent, a monolith or a packed bed of beads retained by frits, tube constrictions, or a magnetic field [7,8].…”