Mass spectrometry (MS) is a set of analytical techniques capable of separating ions in relation to their mass-to-charge ratio (m/z) using appropriate magnetic fields. The functional part of the MS is represented by the mass spectrometer which essentially consists of a sample introduction system, an ionization chamber, an analyzer, and a detector. Considering that the analyzed samples often derive from the separation of mixtures, the mass spectrometer is usually combined with the main chromatographic separation techniques: gas chromatography (GC) and liquid chromatography (LC). The result of a mass spectrometry analysis is a mass spectrum, represented by a graph showing different peaks of variable intensity with positions corresponding to a well-defined mass-to-charge ratio. Some of the main information that can be provided by a mass spectrum are: molecular mass, elemental composition, empirical formula, and functional groups.
Structural characterization is fundamental in the pharmaceutical chemical sector. In fact, determining the molecular structure of a drug is essential to understanding its function, efficacy, and the possibility of releasing potentially toxic substances. In this regard, ultra-high-resolution mass spectrometry proves to be a very valuable ally.
The applications of mass spectrometry are many, they can be used to determine small molecules (molecular mass < 1200 Da) of different natures, but above all to molecules of great biopharmaceutical interest, such as proteins, antibodies, and nucleic acids. In particular, the use of fourier transform ion cyclotron resonance analyzers(FT-ICR MS) and orbitrap shows numerous advantages in the study of drug formulation. The very high sensitivity and the possibility of performing fragmentations allows to determine impurities at very low concentrations and to perform chemical characterizations related the fine distribution of ions, providing great accuracy in the determination of molecular formula.
In recent years, the scientific literature related to ultra-high resolution mass spectrometry has grown rapidly, indicating the numerous potentialities offered by this highly advanced analyte technique.
References
- Estelle Deschamps, Valentia Calabrese, Isabelle Schmitz, Marie Hubert-Roux, Denis Castagnos, Carlos Afonso. Advances in Ultra-High-Resolution Mass Spectrometry for Pharmaceutical Analysis, 2023.
- Steen Hansen, Stig Pedersen-Bjergaard, Knut Rasmussen. Introduction to Pharmaceutical Chemical Analysis, 2012.