Definition

Noun: A graphical representation or data plot showing the relative abundances of ions (charged particles) as a function of their mass-to-charge ratio (m/z). It is the fundamental output of an analytical instrument called a mass spectrometer, used to identify the amount and type of chemicals present in a sample.

Usage

The term "mass spectrum" is used to describe the specific pattern of peaks produced by a mass spectrometer. Each peak corresponds to ions of a particular mass-to-charge ratio, and its height or area indicates the relative abundance of those ions.

Examples

• The chemist analyzed the mass spectrum to determine the molecular weight of the unknown compound.
• A characteristic mass spectrum of the drug was used as a fingerprint for its identification.
• The mass spectrum showed a strong peak at m/z 78, corresponding to the benzene ion.

Advanced Usage

• Interpret a mass spectrum: To analyze the pattern of peaks to deduce structural information about molecules.
  • Interpreting the mass spectrum revealed the presence of chlorine atoms due to the isotopic pattern.
• Obtain/acquire a mass spectrum: The process of running a sample through a mass spectrometer to generate this data.
  • We will acquire a mass spectrum of the purified sample to confirm its identity.

Variants and Related Words

• Mass Spectrometry (n): The field of science and the technique concerned with separating and analyzing ions based on their mass-to-charge ratios to generate a mass spectrum.
• Mass Spectrometer (n): The instrument used to perform mass spectrometry and produce a mass spectrum.
• Mass Spectrograph (n): An older type of instrument that records a mass spectrum on a photographic plate.

Synonyms

• Mass spectral data: A more general term for the information contained in a mass spectrum.
• Ion abundance plot: A descriptive synonym emphasizing the graphical nature of the data.

Related Phrases

• Base peak: The tallest peak in a mass spectrum, assigned a relative abundance of 100%.
• Molecular ion peak (M⁺): The peak corresponding to the intact, ionized molecule, showing its molecular weight.
• Fragmentation pattern: The characteristic set of peaks in a mass spectrum resulting from the breakdown of the molecular ion, crucial for structural elucidation.

Noun

1. a distribution of ions as shown by a mass spectrograph or a mass spectrometer