Source high-performance liquid chromatography

A flow of liquid, for example from high-performance liquid chromatography (HPLC), is treated in such a way that most of the solvent evaporates to leave solute molecules that pass into an ionization region (ion source). 

High performance liquid chromatography (HPLC) has been by far the most important method for separating chlorophylls. Open column chromatography and thin layer chromatography are still used for clean-up procedures to isolate and separate carotenoids and other lipids from chlorophylls and for preparative applications, but both are losing importance for analytical purposes due to their low resolution and have been replaced by more effective techniques like solid phase, supercritical fluid extraction and counter current chromatography. The whole analysis should be as brief as possible, since each additional step is a potential source of epimers and allomers. 

Although saponification was found to be unnecessary for the separation and quantification of carotenoids from leafy vegetables by high performance liquid chromatography (HPLC) or open column chromatography (OCC), saponification is usually employed to clean the extract when subsequent purification steps are required such as for nuclear magnetic resonance (NMR) spectroscopy and production of standards from natural sources. 

Reversed-phase high-performance liquid chromatography (HPLC) column 50 mm x 3.2-mm i.d. with Kromasil 5- um Gig packing High-performance liquid chromatograph coupled to a triple-quadrupole mass spectrometer with an atmospheric pressure chemical ionization (APCI) source Gel permeation chromatograph with a 60 mm x 25-mm i.d. column packed with Bio-Beads SX-3 (50-g)... 

Fig. 1.2 Analysis systems, high-performance liquid chromatography Source Own files...

PAGE Phe Pro PSD QC Q-ToF Q-ToF-LC-MS-MS polyacrylamide gel electrophoresis phenylalanine proline post-source decay quality control quadrupole time-of-flight mass analyser quadrupole time-of-flight mass analyser in combination with (high performance) liquid chromatography and tandem mass... 

In the last twenty years, many of the developed and validated high performance liquid chromatography methods with conventional diode array or fluorescence detectors (DAD, FLD) were improved and substituted by new hyphenation with mass spectrometric instrumentation and/or NMR, especially for the analyses of raw materials derived from Natural sources. The main goal of this coupling is achieved by improvement of selectivity and sensitivity of new instrumental configurations [7], Furthermore, with these configurations it is possible to obtain, in only one analysis, the complete chemical structure elucidation, identification and quantification of targeted compounds. 

A gas chromatograph with a capillary column coupled to a mass spectrometer is an ideal analytical partnership. Effluent from the column has an elevated temperature and the molecules of interest are in a vapor state and ready to enter the ion source. This eliminates the need for desolvation that is required in high-performance liquid chromatography (HPLC)-MS. 

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. 

SOURCES L. R. Snyder, in High-Performance Liquid Chromatography (C. Horvath, ed.), Vol. 3 (New York Academic Press. 1983) Burdick Jackson Solvent Guide, 3rd ed. (Muskegon, MI Burdick Jackson Laboratories, 1990). 

Shin, T.S. and Godber, J.S. 1994. Isolation of four tocopherols and four tocotrienols from a variety of natural sources by semi-preparative high performance liquid chromatography. J. Chromatogr. A 678 49-58. 

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