High pressure chromatography-coupled mass

The use of separation techniques, such as gel permeation and high pressure Hquid chromatography interfaced with sensitive, silicon-specific aas or ICP detectors, has been particularly advantageous for the analysis of siUcones in environmental extracts (469,483—486). Supercritical fluid chromatography coupled with various detection devices is effective for the separation of siUcone oligomers that have molecular weights less than 3000 Da. Time-of-flight secondary ion mass spectrometry (TOF-sims) is appHcable up to 10,000 Da (487). 

The most commonly used method for the identification of carotenoids is high-pressure liquid chromatography (HPFC) combined with the UV-Vis absorption detection. The introduction of diode array detection enabled parallel collection of pigment spectra, which greatly aids the quantification and localization of unknown compounds. Coupling HPFC with the mass-spectrometer significantly... 

W.E. Neff, W.C. Byrdwell, Characterization of model triacylglycerol (triolein, trilinolein and trilinolenin) autoxidation products via high performance liquid chromatography coupled with atmospheric pressure chemical ionization mass spectrometry, Journal of Chromatography A, 818, 169 186 (1998). 

Henchiz Y. Guillarme D. Martel S. Rudaz S. Veuthey J-L. Carrupt P-A. Fast log P determination by ultra-high-pressure liquid chromatography coupled with UV and mass spectrometry detections. Analytical andBioanalytical Chemistry, 2009, 394, 1919-1630. 

Mass spectrometry (MS) is probably a famhiar tool to chemistry and biology students as a technique commonly used to measure the molecular mass of a sample. Often, MS is used in tandem with other techniques for chromatic separation of the sample before mass measurement. Some common hyphenated techniques include HPLC-MS, high-pressure liquid chromatography coupled to MS GC-MS, gas chromatography coupled to MS or CE-MS, capillary electrophoresis coupled to MS. 

Numerous analyses in the quality control of most kinds of samples occurring in the flavour industry are done by different chromatographic procedures, for example gas chromatography (GC), high-pressure liquid chromatography (fiPLC) and capillary electrophoresis (CE). Besides the different IR methods mentioned already, further spectroscopic techniques are used, for example nuclear magnetic resonance, ultraviolet spectroscopy, mass spectroscopy (MS) and atomic absorption spectroscopy. In addition, also in quality control modern coupled techniques like GC-MS, GC-Fourier transform IR spectroscopy, HPLC-MS and CE-MS are gaining more and more importance. 

Lacker T, Strohschein S and Albert K, Separation and identification of various carotenoids by C30 reversed-phase high-performance liquid chromatography coupled to UV and atmospheric pressure chemical ionization mass spectrometric detection. J Chromatogr A 854 37 14 (1999). 

Figure 4 Schematic diagram of high-pressure liquid chromatography inductively coupled plasma mass spectrometry (HPLC-ICP-MS) system with dual-inlet system for isotope dilution analyses. (From Ref. 32.)...

MALDI and ESI represent the predominant ionization techniques in mass spectrometry-based proteomics, as recognized by the Nobel Prize in chemistry in 2002. MALDI is mainly used to volatize and ionize simple polypeptide samples for mass spectrometric (MS) analysis at high speed. The analysis of more complex peptide mixtures is usually conducted via ESI mass spectrometry (ESI MS) coupled online with a high-pressure liquid chromatography (HPLC) system to concentrate and separate peptides prior to MS analysis. 

Timperio, A.M., Magro, P., Chilosi, G. and Zolla, L. (2006) Assay of ochratoxin A in grape by high- pressure liquid chromatography coupled on line with an ESI-mass spectrometry,/. Chromatogr. B, 832 (1), 127-133. 

In recent years, several techniques have been developed for mass spectrometry, whereby samples are ionized and analysed from a condensed phase, without prior volatilization. These desorption techniques have permitted the extension of mass spectrometric analyses to sulfate and glutathione conjugates, as well as to underivatized and labile glucuronic acid conjugates. Primary among these techniques are field desorption 6, plasma desorption (7), laser desorption (8), fast atom bombardment (or secondary ion mass spectrometry with a liquid sample matrix) ( ) and thermospray ionization ( O). The latter can also serve to couple high pressure liquid chromatography and mass spectrometry for analysis of involatile and thermally labile samples. 

M. J. Powell, D. W. Boomer, and D. R. Wiedcrin. Determination of chromium species in environmental. samples using high-pressure liquid chromatography direct injection nebulization and inductively coupled plasma mass spectrometry. Anal. Chern., 67, 2474,1995. 

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