Chromatography-based on- and in-line pre-concentration methods in capillary electrophoresis

Saavedra, Luis Celi; Barbas, Coral

doi:10.1016/j.jbbm.2006.11.005

Cited by 45 publications

(43 citation statements)

References 39 publications

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“…The advantages of applying an electrical dc voltage during the SPE elution step, has been partially observed in oncapillary preconcentration techniques [13,24,25]. These techniques consist of two distinct steps.…”

Section: Voltage-assisted Spementioning

confidence: 99%

Electrical field‐assisted solid‐phase extraction coupled on‐line to capillary electrophoresis‐mass spectrometry

et al. 2008

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A substantial demand currently exists for analytical methods affording the determination of very low concentrations of analytes in complex matrices, such as those of environmental and biological samples, as simply as possible. However, the pretreatment of complex samples, which is unavoidable prior to CE-MS analysis, is usually complicated and time-consuming. In this work, we used voltage-assisted SPE for the first time as an alternative to conventional treatments for preconcentrating and purifying analytes. To this end, we used a simple flow system coupled on-line to CE-MS equipment. The system is quite robust and provides reproducible peak areas (the precision ranges from 2.5 to 3.8%). Also, it provides increased sensitivity affording the determination of trace amounts (nanogram per liter levels) of analytes in only a few milliliters of sample. The proposed system was applied to the determination of members of two compound families (viz. tetracyclines and amines).

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Section: Voltage-assisted Spementioning

confidence: 99%

Electrical field‐assisted solid‐phase extraction coupled on‐line to capillary electrophoresis‐mass spectrometry

et al. 2008

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“…More sensitive detection methods, such as laser-induced fluorescence or mass spectrometry are also frequently used [2,3]. 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].…”

Section: Introductionmentioning

confidence: 99%

Bubble cell for magnetic bead trapping in capillary electrophoresis

Gassner

Proczek

2011

Anal Bioanal Chem

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A bubble cell capillary classically used to extend the optical path length for UV-vis detection is employed here to trap magnetic beads. With this system, a large amount of beads can be captured without inducing a strong pressure drop, as it is the case with magnetic beads trapped in a standard capillary, thereby having less effect on the experimental conditions. Using numerical simulations and microscopic visualizations, the capture of beads inside a bubble cell was investigated with two magnet configurations. Pressure-driven and electro-osmotic flow velocities were measured for different amounts of protein-A-coated beads or C18-functionalized beads (RPC-18). Solid-phase extraction of a model antibody on protein-A beads and preconcentration of fluorescein on RPC-18 beads were performed as proof of concept experiments.

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“…Particularly, on-line solid-phase extraction capillary electrophoresis (SPE-CE) using a microextractor (named ''analyte concentrator'') has successfully been applied to the analysis of numerous compounds [16][17][18][19]. For fabrication of an analyte concentrator, different types of ligands can be immobilized directly on a portion of the inner surface of the capillary wall [20,21], a membrane [22], beads [23][24][25][26][27][28][29][30], multi-bore capillary [31],] or monolithic roads [32][33][34].…”

Section: Introductionmentioning

confidence: 99%

On‐line solid phase extraction CZE for the simultaneous determination of lanthanum and gadolinium at picogram per liter levels

et al. 2009

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A non-specific on-line method is presented for the extraction and preconcentration of two rare earth elements using a microcartridge containing C(18)-derivatized silica particles prior to their analysis by CZE. The microcartridge, named analyte concentrator, was coupled on-line to the inlet of the separation capillary (fused-silica (FS) capillary, 75 microm id x12 cm from the inlet to the microcartidge and 37 cm from the microcartridge to the detector). The reversed-phase sorbent quantitatively retained gadolinium (Gd) and lanthanum (La) as 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol complexes in the presence of non-ionic micelles of polyethylene glycol tert-octylphenyl ether, enabling sample clean-up and concentration enhancement with minimum sample handling. The rare earth elements chelates were released from the sorbent with methanol and then analyzed by CZE with diode array detection. A background electrolyte of 20 mM sodium tetraborate containing 8% ACN, pH 9.0, was found to be optimal for the separation of metal chelates. The concentration limits of detection were lowered to picogram per liter levels (20 pg/L for La and 80 pg/L for Gd). A 1000-fold improvement in concentration sensitivity for La- and Gd-2-(5-bromo-2-pyridylazo)-5-diethylaminophenol complexes with respect to CZE without preconcentration was reached.

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Chromatography-based on- and in-line pre-concentration methods in capillary electrophoresis

Cited by 45 publications

References 39 publications

Electrical field‐assisted solid‐phase extraction coupled on‐line to capillary electrophoresis‐mass spectrometry

Electrical field‐assisted solid‐phase extraction coupled on‐line to capillary electrophoresis‐mass spectrometry

Bubble cell for magnetic bead trapping in capillary electrophoresis

On‐line solid phase extraction CZE for the simultaneous determination of lanthanum and gadolinium at picogram per liter levels

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