Title (Croatian), Kapilarna elektroforeza u farmaciji. Author, Damić, Miranda Nigović, Biljana. Abstract (Croatian). Capillary electrophoresis is a new separation. Elektroforeza kapilarna (CE) to metoda analityczna o bogatej historii. Jest popularna w laboratoriach ze względu na swój ekologiczny charakter, niezawodność. Kupryszewski, J. Barciszewski, Capillary electrophoresis: a new tool for biomolecule separation (Elektroforeza kapilarna: nowe narzedzie analizy biomolekul).
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Capillary electrophoresis CE can be used to separate ionic species by their charge and frictional forces. In traditional electrophoresis, electrically charged analytes move in a conductive liquid medium under the influence of an electric field. Introduced in the s, the technique of capillary electrophoresis CE was designed to separate species based on their size to charge ratio in the interior of a small capillary filled with an electrolyte. Instrumentation The instrumentation needed to perform capillary electrophoresis is relatively simple.
The system’s main components are a sample vial, source and destination vials, a capillary, electrodes, a high-voltage power supply, a detector, and a data output and handling device.
The source vial, destination vial and capillary are filled with an electrolyte such as an aqueous buffer solution. To introduce the sample, the capillary inlet is placed into a vial containing the sample and then returned to the kaoilarna vial sample is introduced into the capillary via capillary action, pressure, or siphoning. The migration of the analytes is then initiated by an electric field that is epektroforeza between the source and destination vials and is supplied to the electrodes by the high-voltage power supply.
It is important to note that all ions, positive or negative, are pulled through the capillary in the same direction by electroosmotic flow, as will be explained.
The analytes separate as they migrate due to their electrophoretic mobility, as will be explained, and are detected near the outlet end of the capillary. The output of the detector is sent to a data output and handling device such as an integrator or computer.
The data is then displayed as an electropherogram, which reports detector response as a function of time. Separated chemical compounds appear as peaks with different retention times in an electropherogram. Detection Separation by capillary electrophoresis can be detected by several detection devices.
In these systems, a section of the capillary itself is used as the detection cell. The use of on-tube detection enables detection of separated analytes with no loss of resolution.
In general, capillaries kapilarma in capillary electrophoresis are kapilarba with a polymer for increased stability. The portion of the capillary used for UV detection, however, must be optically transparent.
Bare capillaries can break relatively easily and, as a result, capillaries with transparent coatings are available to increase ka;ilarna stability of the cell window. According to the Beer-Lambert law, the sensitivity of the detector is proportional to the path length of the cell.
To improve the sensitivity, the path length can be increased, though this results in a loss of resolution. The capillary tube itself can be expanded at the detection point, creating a “bubble cell” with a longer path length or additional kapilxrna can be added at the detection point. Both of these methods, however, will decrease the resolution of the separation. Fluorescence detection can also be used in capillary electrophoresis for samples that naturally fluoresce or are chemically modified to contain fluorescent tags.
This mode of detection offers high sensitivity and improved selectivity for these samples, but cannot be utilized for samples that do not fluoresce. The set-up for fluorescence detection in a capillary electrophoresis system can be complicated.
The method requires that the light beam be focused on the capillary, which can be difficult for many kapilarnna sources. The sensitivity of the technique is attributed to the high intensity of the incident light and the ability to accurately focus the light on the capillary. In order to obtain the identity eletkroforeza sample components, capillary electrophoresis can be directly coupled with mass spectrometers or Surface-Enhanced Raman Spectroscopy SERS.
Elektroosmoza — Википедија, слободна енциклопедија
In most systems, the capillary outlet is introduced into an ion source that utilizes electrospray ionization ESI. The resulting ions are then analyzed by the mass spectrometer. This set-up requires volatile buffer solutions, which will affect the range of separation modes that can be employed and the degree of resolution that can be achieved. The measurement and analysis are mostly done with a specialized gel analysis software.
Analyte retention times can be translated into spatial distance by moving the SERS-active substrate at a constant rate during capillary electrophoresis. This allows the subsequent spectroscopic technique to be applied to specific eluants for identification with high sensitivity.
SERS-active substrates can be chosen that do not interfere with the spectrum of the analytes. Related techniques Elektroflreza discussed above, separations in a capillary electrophoresis system are typically dependent on the analytes having different electrophoretic mobilities.
However, some classes of analyte cannot be separated by this effect because they are neutral uncharged or because they may not differ significantly in electrophoretic mobility. However, there are several techniques that can help separate such analytes with a capillary lapilarna system.
Adding a surfactant to the electrolyte can facilitate the separation of neutral compounds by micellar electrokinetic chromatography.
Charged polymers such elektroofreza DNA can be separated by filling the capillary with a gel matrix that retards longer strands more than shorter strands. This is called capillary gel electrophoresis. This is a high-resolution alternative to slab gel electrophoresis. Some capillary electrophoresis systems can also be used for microscale liquid chromatography or capillary electrochromatography.
A capillary electrophoresis system can also be used for isotachophoresis and isoelectric focussing. E Strona czytana razy.
Glad to find this definition hotmail email login. Site powered by GuppY v4. E – Elektroforeza kapilarna ang.