Liquid chromatography/mass spectrometry conditioning

Figure 5.6 Positive-ion electrospray spectrum obtained from the major component in the LC-MS analysis of a purified recombinant 62 kDa protein using a Cig microbore 50 X 1 mm column and a flow rate of 50 p.lmin . The starting buffer (buffer A ) was 0.1% TEA in water, while the gradient buffer (buffer B ) consisted of 0.1% TEA in acetonitrile-water (9 1 vol/vol). The running conditions consisted of 0% B for 5 min, followed by a linear gradient of 100% B for 55 min. Reprinted from J. Chromatogr., B, 685, McAtee, C. P., Zhang, Y., Yarbough, P. O., Fuerst, T. R., Stone, K. L., Samander, S. and Williams, K. R., Purification and characterization of a recombinant hepatitis E protein vaccine candidate by liquid chromatography-mass spectrometry , 91-104, Copyright (1996), with permission from Elsevier Science.

E.M. Thurman, 1. Ferrer, and D. Barcelo, The ionization-continuum diagram a concept for selection of APCl and ESI conditions for HPLC/MS of pesticides , in 17th Montreux Symposium on Liquid Chromatography/Mass Spectrometry, Montreux, Switzerland, November 8-10, 2000 , p. 31 (2000). 

Marcomini et al. [42] studied the aerobic biodegradation mechanisms of different commercial AE blends (linear, oxo- and multibranched alkyl chains) by analysing the metabolites under the same standardised conditions applying liquid chromatography mass spectrometry LC-MS. 

TFA is advantageous in that it enhances the peak shape and efficiency for some polar compounds and its higher volatility is more desirable in liquid chromatography-mass spectrometry (LC-MS) operative conditions. The interfacing of LC methodologies with MS is discussed later in Section 2.3.1.4. 

Liquid chromatography-mass spectrometry (LC-MS) or liquid chromatography-tandem-mass spectrometry (LC-MS/MS) has been in general the technique of choice for the analysis of PFCs. Therein detailed information about the main experimental conditions used for analysis, such as LC-MS/MS precursor-product ion transitions, were reported. 

Many approaches have been used to form ions, both in high-vacuum and near-atmospheric pressure conditions. Electron ionization (El) and chemical ionization (Cl) are ionization techniques used when gas phase molecules can be introduced directly into the analyzer from a gas chromatograph. In other analyses, such as high-performance liquid chromatography-mass spectrometry (HPLC-MS),... 

Gerhold et al. (9) developed research techniques to Identify the biochemical metabolite which conditioned resistance. They used the same plant materials that had been Included In Winner s genetic studies and Stark s research. All plants were grown from seed and were maintained without the use of pesticides. Included In their study was a resistant parent, a homozygous recessive susceptible parent, and their hybrid. In addition, they tested a susceptible parent which had one dominant locus for resistance. Basically their technique Involved the collection of exudate and subsequent analysis by gas- and high-performance-liquid chromatography, mass spectrometry, and nuclear magnetic resonance (NMR) spectroscopy. 

The red pigment is water-soluble, and turns pale blue under alkaline conditions. Consequently, the red pigment in the Actinidia fruits has been believed to be anthocyanins. Liquid chromatography-mass spectrometry analyses revealed that the major anthocyanins are cyanidin 3-0-xylo-(l-2)-galactoside in A. chinensis fruit and cyanidin 3-0-galactoside and cyanidin 3-0-glucoside in A. deliciosa fruit (Monteflori et al, 2005). 

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