mass spectrum
Học thuậtThân thiện
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
- a distribution of ions as shown by a mass spectrograph or a mass spectrometer