MS analysis Q-TOF

An internal mass calibration is generally needed to achieve mass measurement accuracy of 5 to lOppm with a Q-TOF MS analysis [62-64]. Internal calibration is based on mixing one or several internal standards or calibrants of known molecular weight with the analyte and then using the known masses to calibrate the mass measurements of unknowns that coexist in the sample mixture. 

Now we investigate the symplectin active site by using a photoaffinity labeling and the nano-LC-Q-TOF-MS analysis and also study the structure and activity relationship (SAR) between DCT structures and symplectin bioluminescent activities. For the SAR study, we also developed a novel synthetic method for DCT analogs. ... 

Figure 5.31 LC-electrospray-MS-MS spectrum of the column eluate at around 22 min in the analysis of the peptide mixture from the tryptic digest of glycoprotein TIME-EA4 from silkworm diapause eggs. Reprinted from Bioorg. Med. Chem., 10, Kurahashi, T., Miyazaki, A., Murakami, Y., Suwan, S., Franz, T., Isobe, M., Tani, M. and Kai, H., Determination of a sugar chain and its linkage site on a glycoprotein TIME-EA4 from silkworm diapause eggs by means of LC-ESI-Q-TOF-MS and MS/MS , 1703-1710, Copyright (2002), with permission from Elsevier Science.

Wolfender, J. L., Waridel, P., Ndjoko, K., Hobby, K. R., Major, H. J. and Hostettmann, K. (2000). Evaluation of Q-TOF-MS/MS and multiple stage IT-MSn for the dereplication of flavonoids and related compounds in crude plant extracts. Analysis 28 895-906A. 

M. Ibanez, J.V. Sancho, O.J. Pozo, F. Hernandez, Use of Q-TOF-MS in environmental analysis Elucidation of transformation products of triazine herbicides in water after UV exposure. Anal. Chem., 76 (2004) 1328. 

E. Hoyes, S.J. Gaskell, Tutowahc function switching and its usefulness in peptide and protein analysis using direct infusion micro-ESI Q-TOF MS, Rapid Commun. Mass Spectrom., 15 (2001) 1802. 

C. Robbe, C. Capon, B. CoddevUle, J.-C. Michalski, Diagnostic ions for the rapid analysis by nano-ESI-Q-TOF-MS of O-glycans from human mucins. Rapid Commun. Mass Spectrom., 18 (2004) 412. 

In spring 2004 the Daphnia Toximeter deployed at the RIZA monitoring station alongside the River Meuse in Keizersveer (NL) recorded several alarms. Routine chemical analysis did not reveal the identity of the offending compound(s). It took sophisticated chemical analyses, a combination of HPLC-DAD and Q-TOF MS techniques, to identify the so-far unknown contaminant as 3-cyclohexyl- 1,1-dimethylurea. The maximum concentration of this compound in the River Meuse at the time of the alarm was estimated to be 5 ig/L. The response of the Daphnia to this compound was later confirmed... 

From the sequence analysis of symplectin with LC-Q-TOF-MS, MS/MS and cDNA, symplectin has 501 amino acids sequence. Partial degradation of symplectin with trypsin afforded a 40 kDa protein (symplectin A ), which is the C-terminal part of symplectin and still has bioluminescent activity. We suppose that the active site of symplectin exists in the 40 kDa symplectin A. ... 

Li R, Zhou Y, Wu Z, Ding L (2006) ESI-Q TOF-MS/MS and APCI-IT-MS/MS Analysis of Steroid Saponins from the Rhizomes of Dioscorea panthaica. J Mass Spectrom 41 1... 

ESI-TOF/MS is a valuable technique for determination of TTX, although it is not widely used so far in marine toxin determination. In this analysis, a portion of purified TTX (less than 0.05 mg) is dissolved in a small amount of 1% acetic acid, and added to 50% aqueous methanol. ESI-TOF/MS is taken on a Micromass Q-Tof Mass Spectrometer (Tokyo). Recently, TTX in a tree frog Polypedates sp. extract has been successfully analyzed by ESI-TOF/MS analysis (Tanu et al, 2001). As shown in Figure 14, in the spectrum of the toxin, protonated molecular ion peak (M -f H)" " appeared at m/z = 320.1103, suggesting the molecular weight of the toxin to be 319.1025 which agrees well with that of authentic TTX (CnHivNjOs = 319.1016). 

UHPLC-TOF/MS (37) and UHPLC-Q-TOF/MS (quadrupole analyzer combined with time-of-flight [TOF] analyzer) (31,32,35) methods, as described in specialist literature, are used for the sole identification, but not for the quantitative analysis, of polyphenolic compounds in biological samples. More than that, the abovementioned methods are solely used for detection in biological fluids and their metabolites and for the tracking of the metabolic pathways of polyphenols. 

Mass spectrometers with the TOP analyzer are characterized by higher resolution however, it may not be sufficient to confirm or deny the suggested structure of the polyphenols. In this case it is useful to use a quadrupole mass spectrometer with a TOP analyzer (Q-TOF-MS/MS), which provides greater selectivity and provides more information about the detected polyphenols molecule. A UHPLC technique combined with a TOF/MS detector was utilized to identify twenty-three phenolic acids and flavonoids in almonds (56). Taking into account the numerous advantages of UHPLC coupled with various detectors in the analysis of polyphenols in food, it should also be mentioned that there is the possibility of its application in the analysis of the so-called fingerprint technique (an analysis of commercial tea). 

In conclusion, UHPLC-MS has a wide range of applications in the determination of polyphenolic compounds in foods. Highly sensitive chromatographic method coupled with mass spectrometry allows the detection and identification of anthocyanins in wine samples (57). Yet another example is the use of the technology to detect polyphenolic compounds. Q-TOF-MS is an excellent tool for the detection and identification of new polyphenols in food. An appropriate selection of chromatographic parameters allows for the quick detection of a large number of polyphenols, including both those with hydrophilic properties as well as hydrophobic properties. The use of small particle size and small diameter of the column represents a major advance for the selectivity, sensitivity, and speed of analysis of polyphenolic compounds in foods. Table 7.2 summarizes the developed UHPLC methods, which were used for the determination of polyphenolic compounds in foods. 

Currently PCR and mass spectrometry are performed by two separate instruments. However, there is no reason why PCR followed by simple automated cleanup and mass spectrometry cannot be incorporated into a single integrated instrument. Essentially every configuration of the modern ESI mass spectrometer has been used successfully for the analysis of PCR products, from the highest to the lowest resolution involving. Fourier transform ion cyclotron resonance (FTICR), triple quadrupole, quadrupole-time of flight (Q-TOF), and ion trap.22-24 MS discriminates between two structurally related PCR products by MW difference. Mass accuracy is needed to differentiate the... 

Applied Biosystems Q q TOF analyser equipped with a nanoelectrospray ion source for nano ESI MS and nano ESI MS/ MS analysis... 

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