High-performance liquid chromatography equipment used

Liquid chromatography is important because most compounds are not sufficiently volatile The first equipment for high-performance liquid for gas chromatography. High-performance liquid chromatography (HPLC) uses high... 

High-performance liquid chromatography equipped with diode array (HPEC-DAD) and electrospray ionization mass spectrometric detection (ESI-MS(n)) has been used to identify anthocyanins in muscadine grapes (Sandhu et ah, 2010). Six different anthocyanin 3,5-diglucosides were identified in muscadine grape skins (Sandhu et al., 2010). 

Hara K, Hijikata Y, Hiraoka E, et al. Measurement of urinary amino acids using high-performance liquid chromatography equipped with a strong cation exchange resin pre-column. Ann Clin Biochem 1999 36 202-6. 

High-performance liquid chromatography (HPLC) uses high pressure to force eluent through a closed column packed with micrometer-size particles that provide exquisite separations. The analytical HPLC equipment in Figure 22-14 uses columns... 

Only a few milligrams of sample is needed for a analytic work, and the determination is complete in a few minutes using modem high-pressure, high-speed equipment. The technique is known as high performance liquid chromatography (HPLC). 

High-performance liquid chromatography (HPLC) techniques are widely used for separation of phenolic compounds. Both reverse- and normal-phase HPLC methods have been used to separate and quantify PAs but have enjoyed only limited success. In reverse-phase HPLC, PAs smaller than trimers are well separated, while higher oligomers and polymers are co-eluted as a broad unresolved peak [8,13,37]. For our reverse-phase analyses, HPLC separation was achieved using a reverse phase. Cl8, 5 (Jtm 4.6 X 250 mm column (J. T. Baker, http //www.mallbaker.com/). Samples were eluted with a water/acetonitrile gradient, 95 5 to 30 70 in 65 min, at a flow rate of 0.8 mL/min. The water was adjusted with acetic acid to a final concentration of 0.1%. All mass spectra were acquired using a Bruker Esquire LC-MS equipped with an electrospray ionization source in the positive mode. 

The method of complete electrolysis is also important in elucidating the mechanism of an electrode reaction. Usually, the substance under study is completely electrolyzed at a controlled potential and the products are identified and determined by appropriate methods, such as gas chromatography (GC), high-performance liquid chromatography (HPLC), and capillary electrophoresis. In the GC method, the products are often identified and determined by the standard addition method. If the standard addition method is not applicable, however, other identification/determination techniques such as GC-MS should be used. The HPLC method is convenient when the product is thermally unstable or difficult to vaporize. HPLC instruments equipped with a high-sensitivity UV detector are the most popular, but a more sophisticated system like LC-MS may also be employed. In some cases, the products are separated from the solvent-supporting electrolyte system by such processes as vaporization, extraction and precipitation. If the products need to be collected separately, a preparative chromatographic method is use-... 

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