Esi-ms/ms
Esi-ms/ms - Related Videos
01:12
Electrospray Ionization (ESI) Mass Spectrometry
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2024
Higher molecular weight biomolecules are nonvolatile compounds that may decompose before ionizing or vaporizing during mass analysis with conventional electron impact ionization methods. Accordingly, electrospray ionization (ESI) is the favored method for vaporizing and ionizing biomolecules as it circumvents rapid fragmentation and enables the recording of mass signals for the entire biomolecule. ESI utilizes electrical energy to transfer ions from the liquid phase of the sample into the...
13:06
Visualization of miniSOG Tagged DNA Repair Proteins in Combination with Electron Spectroscopic Imaging (ESI)
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Cited by 12 •
2015
Electron spectroscopic imaging can image and distinguish nucleic acid from protein at nanometer resolution. It can be combined with the miniSOG system, which is able to specifically label tagged proteins in transmission electron microscopy samples. We illustrate the use of these technologies using double-strand break repair foci as an example.
05:46
Identification of Pharmaceuticals in The Aquatic Environment Using HPLC-ESI-Q-TOF-MS and Elimination of Erythromycin Through Photo-Induced Degradation
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Cited by 12 •
2018
We present a protocol for non-targeted analysis using time of flight mass spectrometry as a perfect tool to identify pharmaceuticals in waters. We demonstrate the application of UV irradiation for their elimination. Analysis involving irradiation, compound isolation, identification and kinetic modelling of the degradation profiles is illustrated.
11:44
Synthesis and Mass Spectrometry Analysis of Oligo-peptoids
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Cited by 6 •
2018
A protocol is described for the manual synthesis of oligo-peptoids followed by sequence analysis by mass spectrometry.
09:38
Dithranol as a Matrix for Matrix Assisted Laser Desorption/Ionization Imaging on a Fourier Transform Ion Cyclotron Resonance Mass Spectrometer
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Cited by 3 •
2013
Dithranol (DT; 1,8-dihydroxy-9,10-dihydroanthracen-9-one) has previously been reported as a MALDI matrix for tissue imaging of small molecules; protocols for the use of DT for the MALDI imaging of endogenous lipids on the surface of tissue sections by positive-ion MALDI-MS on an ultrahigh-resolution quadrupole-FTICR instrument are provided here.
FAQs
During electrospray, a solution passes through a high-voltage capillary and forms charged droplets. As the solvent evaporates, gas-phase ions are released for mass analysis. This conversion allows compounds in solution to enter the measurement sequence, where the resulting ions can be distinguished according to their mass-to-charge ratios.
The first mass analyzer selects a precursor ion from the ionized sample, and that selected ion is then fragmented. A second analyzer measures the resulting product ions. This staged measurement connects a specific mass-to-charge signal with its fragmentation pattern, increasing molecular specificity within a chemically complex mixture.
An ion’s mass-to-charge ratio helps distinguish signals, but its fragmentation pattern adds structural information. Product ions reveal how the selected precursor behaves during analysis, supporting more specific compound characterization. This is particularly useful when different components in a mixture require additional evidence for identification beyond a single measured ion.
The workflow begins with a compound solution entering the high-voltage capillary, where charged droplets form and solvent evaporation releases gas-phase ions. A first analyzer selects the precursor ion for fragmentation, while a second analyzer measures the product ions. Analysts can then use the combined mass and fragmentation information for compound characterization.
The technique is well suited to complex mixtures and to compounds that are polar or thermally labile. Its solution-based electrospray process and tandem measurement provide both mass-to-charge information and fragmentation patterns. These capabilities make it useful when chemical analysis requires compound specificity as well as detection within a mixture.
In chemistry, ESI-MS/MS supports compound identification, quantitative analysis, reaction monitoring, and characterization. The approach applies to biomolecules, pharmaceuticals, metabolites, and other polar or thermally labile compounds. Researchers can therefore use it to follow chemical changes, assess measured components, and obtain structural information from diverse chemical samples.