High-performance liquid spectroscopy

Coupling of analytical techniques (detectors) to high-performance liquid chromatographic (HPLC) systems has increased in the last tree decades. Initially, gas chromatography was coupled to mass spectrometry (MS), then to infrai ed (IR) spectroscopy. Following the main interest was to hyphenate analytical techniques to HPLC. 

EC = electrical conductivity detector ECD = electron capture detector FPD = flame photometric detector GC = gas chromatography HPLC = high performance liquid chromatography NPD = nitrogen phosphorus detector TID = thermionic detector UV = ultraviolet spectroscopy... 

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. 

Strohschein, S., Pursch, M., and Albert, K., Hyphenation of high performance liquid chromatography with nuclear magnetic resonance spectroscopy for the characterization of (3-carotene isomers employing a Cjq stationary phase, J. Pharm. Biom. Anal., 21, 669, 1999. 

Hentschel, P. et ah. Structure elucidation of deoxylutein 11 isomers by on-line capillary high performance liquid chromatography- H nuclear magnetic resonance spectroscopy, J. Chromatogr. A, 1112, 285, 2006. 

M.E. Lacey, Z. J. Tan, A. G. Webb, J. V. Sweedler 2001, (Union of capillary high-performance liquid chromatography and microcoil nuclear magnetic resonance spectroscopy applied to the separation and identification of terpenoids), J. Chromatogr. A 922(1-2), 139. 

Zhao, Q., Sannier, F., Garreau, I., Lecoeur, C., and Piot, J. M., Reversed-phase high-performance liquid chromatography coupled with second-order derivative spectroscopy for the quantitation of aromatic amino acids in peptides application to hemorphins, /. Chromatogr. A, 723, 35, 1996. 

Because carotenoids are light- and oxygen-sensitive, a closed-loop hyphenated technique such as the on-line coupling of high performance liquid chromatography (HPLC) together with nuclear magnetic resonance (NMR) spectroscopy can be used for the artifact-free structural determination of the different isomers. 

Putzbach, K., Krucker, M., Grynbaum, M. D., Hentschel, P., Webb, A. G., and Albert, K. 2005. Hyphenation of capillary high-performance liquid chromatography to microcoil magnetic resonance spectroscopy—Determination of various carotenoids in a small-sized spinach sample. J. Pharm. Biomed Anal. 38 910-917. 

High performance liquid chromatography (HPLC) and with mass spectrometry (LC-MS) Plasma emission spectroscopy (PES) Scanning electron microscopy (SEM) with elemental X-ray analysis Thermogravimetric analysis (TGA)... 

Stintzing FC, Schieber A and Carle R. 2002. Identification of betalains from yellowbeet (beta vulgaris L.) and cactus pear (Opuntiaficus-indica L. Mill.) by high performance liquid chromatography-electrospray ionization mass spectroscopy. J Agric Food Chem 50 2302—2307. 

Finally, and apart from the importance of micelles in the solubilization of chemical species, mention should also be made of their intervention in the displacement of equilibria and in the modification of kinetics of reactions, as well as in the alteration of physicochemical parameters of certain ions and molecules that affect electrochemical measurements, processes of visible-ultraviolet radiation, fluorescence and phosphorescence emission, flame emission, and plasma spectroscopy, or in processes of extraction, thin-layer chromatography, or high-performance liquid chromatography [2-4, 29-33],... 

Similarly, other cycloadducts of nitrile oxides with C6o were synthesized. The cycloadducts were characterized by 13C NMR spectroscopy and high-resolution fast atom bombardment (FAB) mass spectrometry. It should be mentioned that X-ray structure determination of the 3-(9-anthryl)-4,5-dihydroisoxazole derivative of C6o, with CS2 included in the crystals, was achieved at 173 K (255). Cycloaddition of fullerene C60 with the stable 2-(phenylsulfonyl)benzonitrile oxide was also studied (256). Fullerene formed with 2-PhSC>2C6H4CNO 1 1 and 1 2 adducts. The IR, NMR, and mass spectra of the adducts were examined. Di(isopropoxy)phosphorylformonitrile oxide gives mono- and diadducts with C60 (257). Structures of the adducts were studied using a combination of high performance liquid chromatography (HPLC), semiempirical PM3 calculations, and the dipole moments. 

SILVA, O, GOMES, E.T., WOLFENDER, J.L., MARSTON, A., HOSTETTMANN, K., Application of high performance liquid chromatography coupled with ultraviolet spectroscopy and electrospray mass spectrometry to the characterisation of ellagitannins from Terminalia macroptera roots, Pharm. Res., 2000,17, 1396-1401. 

High-performance liquid chromatography coupled with fluorescence detection [106, 107] or ion-exchange high-performance liquid chromatography with detection by graphite furnace atomic absorption spectroscopy [108] proved to be sensitive methods, but may lack from limitations in separation power and ease of identification of unknown products. 

Various analytical techniques have been employed to determine the drug content in nanoparticles after the separation procedures. High performance liquid chromatography and UV/vis spectroscopy are two of the most extensively used techniques [133], Other techniques used include scintillation counting [186], spectrofluorodensitometry [176], microbiological assays [136], spectrofluorimetry [187], and polarization fluoroimmunanalysis [67],... 

Other combinations of chromatography techniques with MS which may be useful in environmental studies are the coupling of high performance liquid chromatography (LC) with MS [84,384,504,506,530,585-593],LC with MS-MS [181, 594 - 599], LC with atmospheric pressure chemical ionization MS (LC-APCI-MS) [600], and Fourier transform infrared spectroscopy-fast atom bombardment coupled to LC-MS (FTIR-FAB-LC-MS) [514]. 

The ELISA can be used as one component of a battery of analyses. Rarely is only one method used in isolation. Other tests include chromatographic methods such as reversed-phase high-performance liquid chromatography (HPLC), size exclusion chromatography, and physical structure analytical methods such as UV spectral analysis, mass spectroscopy, etc. 

Schulten, H.-R., and Soldati, F. (1981). Identification of ginsenosides from Panax ginseng in fractions obtained by high-performance liquid chromatography by field desorption mass spectrometry, multiple internal reflection infrared spectroscopy and thin layer chromatography. J. Chromatogr. 212, 37-i9. 

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