Analysis by Mass Spectrometry (MS)
Mass spectrometry (MS) is an advanced analytical technique that allows for the identification and quantification of molecules in a sample with extreme precision by measuring their mass-to-charge ratio (m/z) . Widely used for the analysis of trace compounds, the identification of unknown substances, and the structural characterization of complex molecules, mass spectrometry is an essential method in the pharmaceutical, cosmetic, environmental, chemical, food, and materials industries.
What is mass spectrometry?
Mass spectrometry (MS) is a physico-chemical method that involves ionizing the molecules of a sample, then sorting them according to their mass/charge ratio using a mass analyzer , before detecting .
It provides highly accurate data on the molecular mass , chemical structure , ionic fragments , and concentration of the analyzed substances, even at very low levels. Mass spectrometry can be used alone or coupled with separation techniques such as gas chromatography-mass spectrometry (GC-MS), liquid chromatography-mass spectrometry (LC-MS), or inductively coupled plasma mass spectrometry (ICP-MS) for metals.
What analyses can be performed with mass spectrometry?
Identification of unknown substances : detection of contaminants, degradation products or emerging pollutants.
Trace analysis : substances present at ng/g or lower in complex matrices.
Structural characterization : determination of molecular structure, exact weight, functional groups.
Dosage of targeted molecules : active ingredients, hormones, metabolites, additives, organic pollutants.
Regulatory analyses : compliance with pharmacopoeia monographs (Ph. Eur., USP), REACH regulations, EC Regulation 1223/2009, FCM, etc.
How mass spectrometry works
A mass spectrometer comprises three main modules:
- Ionization source The molecules are transformed into ions. The choice of technique depends on the nature of the sample:
- EI (Electron Impact) for volatile compounds (GC-MS)
- ESI (Electrospray Ionization) or APCI for polar or thermosensitive compounds (LC-MS)
- ICP (Inductively Coupled Plasma) for metals (ICP-MS)
- Mass analyzer : sorts ions according to their mass/charge ratio (m/z). Common technologies: quadrupole, TOF, Orbitrap, ion trap.
- Detector : measures ions and generates a mass spectrum representing intensities as a function of m/z.
Technical characteristics of mass spectrometry
- Detection limits : up to pg/g depending on the instrument
- Resolution : high (Orbitrap, TOF) or unit (quadrupole)
- Types of ionization : EI, CI, ESI, APCI, MALDI, ICP…
- Possible couplings : GC-MS, LC-MS, LC-MS/MS, ICP-MS
- Qualitative and quantitative analysis
- Applicable standards : Pharmacopoeias, ISO, REACH, CLP, ICH Q2(R1), FCM, etc.
For which matrices?
Mass spectrometry is suitable for a wide variety of organic and inorganic matrices, whether solid, liquid or gaseous:
Main industrial applications
Mass spectrometry is used in regulatory analyses , R&D , quality control and technical expertise in many industrial sectors:
Léa Géréec
Technical and scientific expert
