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Lecture

Mass Spectrometry: Ion Sources and Analyzers

In course

PHYS-468: Physics of life

Life has emerged on our planet from physical principles such as molecular self-organization, thermodynamics, stochastics and iterative refinement. This course will introduce the physical methods to study life and will discuss the quantitative and physical ...

Description

This lecture on Mass Spectrometry covers the principles of ionization, mass sorting, and analysis according to mass/charge ratio. It explains the operation of various ion sources, analyzers, and detectors, such as Electron Ionization, MALDI, and Quadrupole Mass Filters. The instructor discusses the advantages and disadvantages of different ionization techniques, including Electron Spray Ionization and Chemical Ionization. The lecture also delves into the functioning of instruments like Linear Time-of-Flight and Reflectron Time-of-Flight mass analyzers, highlighting their capabilities and limitations.

Instructor

Henning Paul-Julius Stahlberg

Positions: Since 2020 Prof. Physics, IPHYS, SB, EPFL, Switzerland 2009 – 2021 Prof. Structural Biology, Biozentrum, University Basel, Switzerland 2009 – 2010 Adj. Assoc. Prof. Molecular & Cellular Biology, UC Davis, CA, USA 2007 – 2009 Assoc. Prof. Molecular & Cellular Biology, UC Davis, CA, USA 2003 – 2007 Assist. Prof. Molecular & Cellular Biology, UC Davis, CA, USA Education: 2002 Habilitation, Biozentrum, University Basel, Switzerland 1997 – 2003 Postdoctoral Fellow, Biozentrum, University Basel, Switzerland 1992 – 1997 PhD Student, EPFL, Lausanne, Switzerland 1990 – 1991 Diploma Thesis in Solid State Physics, TU Berlin, Germany 1987 – 1993 Study of Physics, TU Berlin, Germany Selected Awards & Honors: 2009 W.M.Keck Award 2004 CAREER award, NSF, USA 2002 Habilitation, University Basel, Switzerland Selected Memberships: 2008 – 2013 Chancellor’s Fellow Award, UC Davis, CA, USA 2004 – 2009 Faculty of 1000 Since 1992 Swiss Society for Optics and Microscopy (SSOM)

Official source

Ontological neighbourhood

Chemistry

Analytical chemistry: Mass spectrometry

Related concepts (32)

Mass spectrometry

Mass spectrometry (MS) is an analytical technique that is used to measure the mass-to-charge ratio of ions. The results are presented as a mass spectrum, a plot of intensity as a function of the mass-to-charge ratio. Mass spectrometry is used in many different fields and is applied to pure samples as well as complex mixtures. A mass spectrum is a type of plot of the ion signal as a function of the mass-to-charge ratio.

Quadrupole mass analyzer

In mass spectrometry, the quadrupole mass analyzer (or quadrupole mass filter) is a type of mass analyzer originally conceived by Nobel laureate Wolfgang Paul and his student Helmut Steinwedel. As the name implies, it consists of four cylindrical rods, set parallel to each other. In a quadrupole mass spectrometer (QMS) the quadrupole is the mass analyzer - the component of the instrument responsible for selecting sample ions based on their mass-to-charge ratio (m/z).

Tandem mass spectrometry

Tandem mass spectrometry, also known as MS/MS or MS2, is a technique in instrumental analysis where two or more mass analyzers are coupled together using an additional reaction step to increase their abilities to analyse chemical samples. A common use of tandem MS is the analysis of biomolecules, such as proteins and peptides. The molecules of a given sample are ionized and the first spectrometer (designated MS1) separates these ions by their mass-to-charge ratio (often given as m/z or m/Q).

Time-of-flight mass spectrometry

Time-of-flight mass spectrometry (TOFMS) is a method of mass spectrometry in which an ion's mass-to-charge ratio is determined by a time of flight measurement. Ions are accelerated by an electric field of known strength. This acceleration results in an ion having the same kinetic energy as any other ion that has the same charge. The velocity of the ion depends on the mass-to-charge ratio (heavier ions of the same charge reach lower speeds, although ions with higher charge will also increase in velocity).

Matrix-assisted laser desorption/ionization

In mass spectrometry, matrix-assisted laser desorption/ionization (MALDI) is an ionization technique that uses a laser energy-absorbing matrix to create ions from large molecules with minimal fragmentation. It has been applied to the analysis of biomolecules (biopolymers such as DNA, proteins, peptides and carbohydrates) and various organic molecules (such as polymers, dendrimers and other macromolecules), which tend to be fragile and fragment when ionized by more conventional ionization methods.

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