4 edition of High Performance Liquid Chromatography found in the catalog.
|LC Classifications||June 1987|
|The Physical Object|
|Pagination||xvi, 65 p. :|
|Number of Pages||89|
nodata File Size: 4MB.
If the pressure of the HPLC can be limited, nearly every FPLC column may also be used in an HPLC system. Analytes that have the least amount of interaction with the stationary phase or the most amount of interaction with the mobile phase will exit the column faster. High Performance Liquid Chromatography HPLC is a form of column chromatography that pumps a sample mixture or analyte in a solvent known as the mobile phase at high pressure through a column with chromatographic packing material stationary phase.
The sample is carried by a moving carrier gas stream of helium or nitrogen. These systems are faster, more sensitive, and rely on smaller volumes of organic solvents than standard HPLC, resulting in the ability to run more samples in less time.
HPLC has the ability to separate, and identify compounds that are present in any sample that can be dissolved in a liquid in trace concentrations as low as parts per trillion. High Performance Liquid Chromatography manual injection of samples is still possible, most HPLCs are now fully automated and controlled by computer. FPLC columns can only be used up to maximal pressures of 3-5 MPa. Sample retention time will vary depending on the interaction between the stationary phase, the molecules being analyzed, and the solvent, or solvents used.
Nitrogen is used as a nebulisation gas in Evaporative Light Scattering Detector ELSD where the solvent is evaporated from the sample leaving a mist as is measured. Helium sparging is an effective method of degassing the mobile phase to avoid unstable baselines caused by dissolved air. The mobile phase exits the detector and is either sent to a waste, or collected, as desired. A detector is needed to see the separated compound bands as they elute from the high pressure column.
There are usually a minimum of two reservoirs in a system, with each holding up to 1000 cc of solvent and usually fitted with a gas diffuser through which helium can be bubbled. As the sample passes through the column it interacts between the two phases at different rate, primarily due to different polarities in the analytes.
The packing material is referred to as the stationary phase because it is held in place by the column hardware.
uHPLC is also known as UPLC TM, a trademark of the Waters Corporation. The injector, or auto sampler, introduces the solvent into a phase stream that carries the sample into the high pressure up to 400 bar column, which contains specific packing material needed to effect separation. Fast protein liquid chromatography FPLC : FPLC is a system similar to high-performance liquid chromatography that is used to separate or purify proteins and other biomolecules from complex mixtures.
However, if the systems are run at typical pressures greater than 800 bar, the columns age, or degrade quicker. A pump is used to generate a specified flow of the mobile phase.
Nitrogen is used as a nebulisation gas in Evaporative Light Scattering Detector ELSD where the solvent is evaporated from the sample leaving a mist as is measured.