Mass Spectrometry

Flashcards covering key terms and concepts from the lecture on Mass Spectrometry.

Mass Spectrometry

A technique for studying the masses of atoms or fragments of molecules.

m/z

The mass-to-charge ratio, a key value displayed in mass spectra.

Nominal Mass

The integer mass of a molecule calculated using the most abundant isotope.

Dalton (Da)

A unit of mass used in mass spectrometry, equivalent to 1/12 of the mass of a carbon-12 atom.

Ionization

The process of converting molecules into ions, often necessary for mass spectrometry.

Electron Impact Ionization (EI)

A common ionization technique involving bombarding a gas with high-energy electrons.

Chemical Ionization (CI)

A softer ionization technique compared to EI, often using gases like methane or ammonia.

Resolving Power

The ability of a mass spectrometer to distinguish between different ions based on their m/z values.

Quadrupole Mass Separator

An arrangement of rods that filters ions based on their mass-to-charge ratio by varying electric fields.

Time-of-Flight (ToF)

A type of mass spectrometer that measures the time it takes for ions to travel to the detector.

Electrospray Ionization (ESI)

A method of ionizing liquid samples for mass spectrometry, enabling the generation of charged droplets.

Matrix-Assisted Laser Desorption/Ionization (MALDI)

An ionization method used commonly for large biological molecules involving a matrix that absorbs UV light.

Fragmentation Patterns

Patterns observed in mass spectrometry that show different ways in which a molecule can break apart.

Isotopologues

Molecules that have the same molecular structure but differ in isotopic composition.

Base Peak

The peak in a mass spectrum that represents the most abundant ion.

Molecular Ion Peak (M+)

The peak formed by the intact ion of the analyte molecule in mass spectrometry.

Degree of Unsaturation

A measure of the number of rings and pi bonds in a molecule, impacting its mass spectrum.

Soft Ionization

Techniques that produce ions with minimal fragmentation, preserving the parent ion structure.

Hard Ionization

Techniques that produce a high degree of fragmentation of the parent molecule.

Proton Donor

A species that can donate a proton during chemical ionization, facilitating ion formation.

Sampling Methods in Mass Spectrometry

Various techniques like MALDI, ESI, and DART used to prepare samples for analysis.