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ESI-TOF

Kato, S., Oba, Y., Ojika, M., and Inouye, S. (2004). Identification of the biosynthetic units of Cypridina luciferin in Cypridina (Vargula) hilgen-dorfii by LC/ESI-TOF-MS. Tetrahedron 60 11427-11434. [Pg.409]

The loop for the 2nd-D was loaded with the effluent of the 1 st-D at 50 pL/min for 1 min 58 s, and then the injection valve was turned to inject the 100 pL fraction for 2 s onto the 2nd-D HPLC. The flow rate was 5 mL/min, and the valve was turned back for the next loading, resulting in fractionation of the lst-D every 2 min. In this case less than 2% of the effluent from the 1 st-D was wasted during sample injection. The 2nd-D effluent eluted at 5 mL/min from the 2nd-D column, passed through a UV detector, and then was split by using a T-joint at approximately a 1/140 split ratio, resulting in a flow rate of ca. 36 pL/min going into the spray capillary for ESI-TOF-MS detection. [Pg.167]

Online LC-ESI-TOF-MS experiments are carried out in a very similar fashion to the off-line NPS-HPLC separations described above, with a few notable exceptions. Firstly, 0.3% (v/v) formic acid is added to each mobile phase to counteract the ionization suppression induced by TFA. Because of the formic acid UV detection must be carried out at 280 nm (as opposed to 214 nm). To aid in normalization between runs 1 jag of Bovine insulin (MW = 5734 Da) is added to each chromatofocusing fraction prior to injection onto the column. Finally, the flow is split postcolumn directing 200 JlL/min into the ion source and the remaining 300 JlL/min through the UV detector and fraction collection. [Pg.228]

As described above all samples were separated online using LCT ESI-TOF-MS then normalized for relative quantitation using a bovine insulin internal standard. Fractions were then collected for MAFDI-TOF-MS PMF, digested with modified porcine trypsin, and analyzed using the TofSpec2E. Following this analysis, three major classes of differentially expressed including proteins were revealed in these... [Pg.236]

This chapter has presented several comprehensive 2DLC approaches combining a first-dimension IEX separation and a second-dimension RP separation for the analysis of complex protein mixtures typical in proteomics studies. Online ESI-TOF/MS detection provided sensitive detection and valuable qualitative information (MW) for proteins eluting from the MDLC system. Coordinated fraction collection and subsequent MS analysis of peptides produced by proteolysis of the fractions provided in-depth information on protein identification and a mechanism... [Pg.311]

Example UV photodiode array (PDA) and ESI-TOF detection can be combined if the effluent is split or the PDA precedes the ESI interface. The detection methods complement each other in that their different sensitivities towards components of a mixture prevent substances from being overlooked. RICs help to differentiate a targeted compound - an unknown impurity in this case - from others and to identify eventually present isomers. Finally, accurate mass measurement helps in the identification of the unknown (Fig. 12.9). [25]... [Pg.486]

Since the limit of detection for small molecule ligands, with modern ESI-Tof mass spectrometers, is approximately 0.05 pM, the concentration of the protein-ligand complex prior to the GPC spin column treatment must be about 0.25 pM. For initial protein and ligand concentrations >5 pM, this corresponds to values <20 pM, as indicated in Fig. 2.3. This is a desirable region for the GPC spin column studies, since one wants to be certain to detect ligands from the stronger as well as the weakest ligand binders. [Pg.71]

As we optimized Tethering we used a variety of mass spectrometers. In our experience, the sensitivity and high resolution of TOP analyzers has provided the most rapid and accurate analyses of intact proteins. An example of an ESI-TOF data set from a standard experiment is illustrated in Fig. 9.2. Figure 9.2A is the deconvoluted mass spectrum of a Cys-mutant target protein after equilibration... [Pg.307]

Part IV covers the relevance of new combination (i.e., hyphenation) techniques such as CE-ESI- (electrospray ionization) MS (mass spectrometry) and CE-ESI-TOF- (time of flight) MS for ACE. [Pg.12]

Notes MS techniques are usually designated by the ionization source producing the ions (e.g., FAB, MALDI, ESI, APCI) and by the mass analyzer (e.g., TOF, IT) used to sort them according to their miz values (e.g., MALDI-TOF, ESI-TOF, ESI-IT). Two analyzers are used in series in tandem MS (MS-MS) techniques (e.g., ESI-Q-TOF). [Pg.85]

The complementary use of LC-ESI-ToF-MS and hyphenated ICP-MS with dynamic reaction cell (DRC) for the characterization of native and recombinant copper proteins (of molar mass range 10-20kDa) has been investigated by Hann et al.67 Size exclusion chromatography (SEC) and ion chromatography (IC) were implemented as separation techniques for hyphenated ICP-MS of intact Cu containing proteins. [Pg.329]

Electrospray ionization time-of-flight mass spectrometry (ESI ToF MS). 338... [Pg.327]

S. F. Wheeler and D. J. Harvey, Negative ion mass spectrometry of sialylated carbohydrates Discrimination of A -acetylneuraminic acid linkages by MALDI-TOF and ESI-TOF mass spectrometry, Anal. Chem., 72 (2000) 5027-5039. [Pg.128]

The ESI-LC/MS-based approaches that feature ion trap (Gatlin et al, 1998 Washburn et ah, 2001) and quadrupole time-of-flight (QTOF) (Blackburn and Moseley, 1999) mass spectrometers are routinely used for the identification and characterization of proteins. Nanoelectrospray LC/MS formats (Figure 6.3) are used to provide lower limits of detection and fully automated sample preconcentration and desalting. On-line LC/MS approaches for protein expression profiling are also used with ESI-TOF (Banks and Gulcicek, 1997 Chong et al., 2001) and ESI-Fourier transform (FT) (Kelleher... [Pg.75]


See other pages where ESI-TOF is mentioned: [Pg.61]    [Pg.167]    [Pg.168]    [Pg.228]    [Pg.230]    [Pg.293]    [Pg.308]    [Pg.308]    [Pg.311]    [Pg.88]    [Pg.42]    [Pg.410]    [Pg.230]    [Pg.231]    [Pg.240]    [Pg.241]    [Pg.184]    [Pg.487]    [Pg.70]    [Pg.116]    [Pg.308]    [Pg.84]    [Pg.344]    [Pg.190]    [Pg.343]    [Pg.129]    [Pg.479]    [Pg.76]    [Pg.358]    [Pg.361]    [Pg.365]    [Pg.225]    [Pg.241]    [Pg.241]   
See also in sourсe #XX -- [ Pg.84 , Pg.88 , Pg.89 , Pg.90 , Pg.136 , Pg.137 , Pg.138 , Pg.215 , Pg.216 , Pg.217 , Pg.218 , Pg.219 , Pg.220 ]

See also in sourсe #XX -- [ Pg.75 ]




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