High Resolution Mass Spectrometry
High Resolution Mass Spectrometry - Related Videos
01:15
High-Resolution Mass Spectrometry (HRMS)
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2024
The resolution of a mass spectrometer depends on the efficiency of separating ions with different ion masses. The mass of an atom is approximated to the sum of the masses of protons and neutrons inside, considering the masses of protons and neutrons as equal. However, the masses of the proton (1.6726 × 10−24 g) and neutron (1.6749 × 10−24 g) are not truly equal. There is a minor error in the expression of atomic masses relative to the simplest atom of hydrogen. For example, the mass of helium...
07:09
Tandem Mass Spectrometry
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2023
In tandem mass spectrometry a biomolecule of interest is isolated from a biological sample, and then fragmented into multiple subunits in order to help elucidate its composition and sequence. This is accomplished by having mass spectrometers in series. The first spectrometer ionizes a sample and filter ions of a specific mass to charge ratio. Filtered ions are then fragmented and passed to a second mass spectrometer where the fragments are analyzed. This video introduces the principles of...
07:27
MALDI-TOF Mass Spectrometry
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2023
Matrix-assisted laser desorption ionization (MALDI) is a mass spectrometry ion source ideal for the analysis of biomolecules. Instead of ionizing compounds in the gaseous state, samples are embedded in a matrix, which is struck by a laser. The matrix absorbs the majority of the energy; some of this energy is then transferred to the sample, which ionizes as a result. Sample ions can then be identified using a time-of-flight analyzer (TOF). This video covers principles of MALDI-TOF, including...
13:45
Introduction to Mass Spectrometry
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2023
Source: Laboratory of Dr. Khuloud Al-Jamal - King's College London Mass spectrometry is an analytical chemistry technique that enables the identification of unknown compounds within a sample, the quantification of known materials, the determination of the structure, and chemical properties of different molecules. A mass spectrometer is composed of an ionization source, an analyzer, and a detector. The process involves the ionization of chemical compounds to generate ions. When using...
11:00
Untargeted Metabolomics from Biological Sources Using Ultraperformance Liquid Chromatography-High Resolution Mass Spectrometry (UPLC-HRMS)
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Cited by 33 •
2013
Untargeted metabolomics provides a hypothesis generating snapshot of a metabolic profile. This protocol will demonstrate the extraction and analysis of metabolites from cells, serum, or tissue. A range of metabolites are surveyed using liquid-liquid phase extraction, microflow ultraperformance liquid chromatography/high-resolution mass spectrometry (UPLC-HRMS) coupled to differential analysis software.
FAQs
Resolving power allows the instrument to separate signals whose mass-to-charge ratios differ only slightly. This capability is especially important when multiple compounds or ions produce nearby peaks, because higher resolution reduces ambiguity in interpreting the spectrum. In practice, it helps analysts distinguish closely related components within chemically complex samples.
Accurate-mass measurements provide a precise mass value that can support assignments of an ion's elemental composition. Chemists can use this information alongside the observed spectrum to evaluate which composition best matches the measured signal. The resulting assignment strengthens identification of unknown compounds and supports molecular-structure characterization.
The measurement depends on three linked stages. Ionization converts molecules into ions, the high-resolution mass analyzer separates those ions according to mass-to-charge ratio, and the detector records the separated signals as a spectrum. Each stage contributes to the final analytical result, connecting the sample's molecular composition with interpretable accurate-mass data.
Isotopic patterns provide additional spectral information beyond a single measured mass. Their presence and arrangement can help chemists evaluate molecular identities and characterize structures, particularly when several candidate compounds have similar masses. Examining these patterns alongside accurate-mass signals improves interpretation of unknowns and supports analysis of complex chemical mixtures.
A typical workflow begins by introducing the sample for ionization, followed by separation of the resulting ions in a high-resolution mass analyzer. The detector then records the signals to generate an accurate-mass spectrum. Analysts interpret the spectrum using mass differences, accurate-mass values, elemental-composition assignments, and isotopic patterns to characterize the sample.
Chemists use HRMS when small mass differences, accurate-mass information, or detailed isotopic patterns are important for interpretation. The technique supports unknown-compound identification, organic synthesis, pharmaceutical research, environmental analysis, metabolomics, and detection of trace components. Its value is greatest when samples contain complex mixtures or when structural characterization requires precise mass information.