Molecular Ion
| Formula / Notation | M⁺ (molecular ion): intact molecule minus one electron; base peak: most abundant fragment |
|---|---|
| Also Known As | M⁺, M⁺• (EI), [M+H]⁺ (ESI), parent ion, molecular ion peak |
What is Molecular Ion?
The ion formed in mass spectrometry when a molecule loses one electron to form M⁺ (radical cation). The molecular ion peak (M⁺) in a mass spectrum corresponds to the molecular mass of the compound and provides the molecular formula when combined with exact mass measurements.
Formula & Notation
Other Names / Synonyms: M⁺, M⁺• (EI), [M+H]⁺ (ESI), parent ion, molecular ion peak
Properties & Characteristics
Uses & Applications
Safety Information
Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.
Key Facts
Frequently Asked Questions
The ion formed in mass spectrometry when a molecule loses one electron to form M⁺ (radical cation). The molecular ion peak (M⁺) in a mass spectrum corresponds to the molecular mass of the compound and provides the molecular formula when combined with exact mass measurements.
The molecular ion peak in MS is used to: determine the molecular mass of a compound, infer the molecular formula (exact mass matching), identify unknowns by database searching, and in environmental analysis to confirm presence of specific target compounds at trace levels.
No direct safety concern. Mass spectrometric molecular ion analysis is used in forensic toxicology to identify drugs of abuse, poisons, and environmental contaminants. Exact mass confirmation is increasingly required in pharmaceutical regulatory submissions (FDA, EMA).
The formula or notation for Molecular Ion is: M⁺ (molecular ion): intact molecule minus one electron; base peak: most abundant fragment