Lesson 33 - Ion Fragments and chemical formulae I - GCMS

Fragment ion

An electrically charged dissociation product of ionic fragmentation that can dissociate further to form other electrically charged molecular or atomic moieties.

Positive ion

An electrically charged atom, radical, or molecule that has lost one or more electrons, acquiring a positive charge.

Negative ion

An atom, radical, or molecule in the vapor phase that has gained one or more electrons, acquiring a negative charge.

Parent ion

An electrically charged molecular moiety that may dissociate to form fragments, which can be electrically charged or neutral.

Daughter ion

An electrically charged product resulting from the reaction of a particular parent (precursor) ion.

Even-electron ion

An ion containing no unpaired electrons.

Radical ion

An ion containing an unpaired electron, making it both an ion and a radical.

Molecular ion

An ion that is formed when an organic molecule loses an electron, resulting in a positively charged ion.

Fragment ion formation

The process by which molecular ions break up into smaller pieces, often resulting in one positive ion and one uncharged free radical.

Chemical formula for fragment ions

A representation that indicates the elemental composition and charge of a fragment ion.

Electron Impact Ionization (EI)

A method of ionization in mass spectrometry where molecules are bombarded with high-energy electrons (70 eV) to form ions.

m/z value

The mass-to-charge ratio of ions detected in mass spectrometry.

Base peak

The most abundant ion in a mass spectrum, which has the highest intensity.

Valence electrons

The outermost electrons of an atom, which determine its chemical properties and bonding behavior.

GCMS

Gas Chromatography-Mass Spectrometry, a technique for analyzing volatile compounds.

Radical

A molecule or ion that has unpaired electrons and is often highly reactive.