Capillary electrophoresis

About: Capillary electrophoresis is a research topic. Over the lifetime, 21396 publications have been published within this topic receiving 590222 citations. The topic is also known as: Label-free HPCE.

Micromachining a Miniaturized Capillary Electrophoresis-Based Chemical Analysis System on a Chip

Abstract: Micromachining technology was used to prepare chemical analysis systems on glass chips (1 centimeter by 2 centimeters or larger) that utilize electroosmotic pumping to drive fluid flow and electrophoretic separation to distinguish sample components. Capillaries 1 to 10 centimeters long etched in the glass (cross section, 10 micrometers by 30 micrometers) allow for capillary electrophoresis-based separations of amino acids with up to 75,000 theoretical plates in about 15 seconds, and separations of about 600 plates can be effected within 4 seconds. Sample treatment steps within a manifold of intersecting capillaries were demonstrated for a simple sample dilution process. Manipulation of the applied voltages controlled the directions of fluid flow within the manifold. The principles demonstrated in this study can be used to develop a miniaturized system for sample handling and separation with no moving parts.

Micromachining a miniaturized capillary electrophoresis-based chemical analysis system on a chip

Abstract: Micromachining technology was used to prepare chemical analysis systems on glass chips (1 centimeter by 2 centimeters or larger) that utilize electroosmotic pumping to drive fluid flow and electrophoretic separation to distinguish sample components. Capillaries 1 to 10 centimeters long etched in the glass (cross section, 10 micrometers by 30 micrometers) allow for capillary electrophoresis-based separations of amino acids with up to 75,000 theoretical plates in about 15 seconds, and separations of about 600 plates can be effected within 4 seconds. Sample treatment steps within a manifold of intersecting capillaries were demonstrated for a simple sample dilution process. Manipulation of the applied voltages controlled the directions of fluid flow within the manifold. The principles demonstrated in this study can be used to develop a miniaturized system for sample handling and separation with no moving parts.

Capillary electrophoresis and sample injection systems integrated on a planar glass chip

Abstract: The feasibillity of miniaturizing a chemical analysis system on a planar substrate has been demonstrated for a system utilizing electrokinetic phenomena for sample separation and solvent pumping. Using micromachining techniques, a complex manifold of capillary channels has been fabricated in a planar glass substrate and the separation of a mixture of fluorescein and calcein within the channels was achieved using electrophoresis. The maximum number of theoretical piates abtained was about 35 000 for calcein, with 5000 V applied, corresponding to 2100 V between the injection and fluorescence detection points in the channels

Capillary zone electrophoresis

Abstract: SUMMARY Capillary electrophoresis offers the possibility of rapid and effective separations in an instrumental format. The two most serious obstacles for future development are the present insufficient detector sensitivity and residual adsorption of solutes to the capillary surface. Capillaries offer some advantages over traditional gel systems. Efficient heat dissipation from capillaries permits the application of unusually high voltages which results in fast and efficient separations. On-line sample injection and detection along with the reusable nature of capillaries makes this format suitable for automation. This could be a significant advantage in situations where repetitive analyses must be run. Capillaries lend themselves to collection of accurate physico-chemical data such as mobilities from migration times and diffusion coefficients from zone widths. They are also an ideal system in which to investigate non-aqueous separation media (ref. 14). Forming gels in a variety of non-aqueous solvents might be difficult, and capillaries offer an uncomplicated approach to the problem. Non-aqueous solvents, although not traditional in electrophoresis, offer exciting possibilities. The wider range of acid and base strengths possible in solvents other than water, as well as the ability to solvate very hydrophobic solutes, could greatly expand the range of substances amenable to electrophoretic separation and analysis.

Liquid-liquid-liquid microextraction for sample preparation of biological fluids prior to capillary electrophoresis.

Abstract: Methamphetamine as a model compound was extracted from 2.5-mL aqueous samples adjusted to pH 13 (donor solution) through a thin phase of 1-octanol inside the pores of a polypropylene hollow fiber and finally into a 25-microL acidic acceptor solution inside the hollow fiber. Following this liquid-liquid-liquid microextraction (LLLME), the acceptor solutions were analyzed by capillary zone electrophoresis (CE). Extractions were performed in simple disposable devices each consisting of a conventional 4-mL sample vial, two needles for introduction and collection of the acceptor solution, and a 8-cm piece of a porous polypropylene hollow fiber. From 5 to 20 different samples were extracted in parallel for 45 min, providing a high sample capacity. Methamphetamine was preconcentrated by a factor of 75 from aqueous standard solutions, human urine, and human plasma utilizing 10(-1) M HCl as the acceptor phase and 10(-1) M NaOH in the donor solution. In addition to preconcentration, LLLME also served as a technique for sample cleanup since large molecules, acidic compounds, and neutral components were not extracted into the acceptor phase. Utilizing diphenhydramine hydrochloride as internal standard, repetitive extractions varied less than 5.2% RSD (n = 6), while the calibration curve for methamphetamine was linear within the range 20 ng/microL to 10 micrograms/mL (r = 0.9983). The detection limit of methamphetamine utilizing LLLME/CE was 5 ng/mL (S/N = 3) in both human urine and plasma.