Contact: Albert Ruggi
Mass Spectrometry (MS) Tips
The choice of the MS technique is of paramount importance to obtain meaningful results.
To make this choice one must consider a few parameters:
- The expected mass* (m/z) of the target molecule
- The most suitable ionization method
- The level of accuracy needed
* “Masses” of molecules in MS (the “numbers” that appear on the x-axis of a mass spectrum) are always expressed in m/z, i.e. the ratio between molecular weight and charge of the species. This means that a molecule with a 2+ charge and a molecular weight of 1000 will be observed at 500 m/z.
Here are some basic indications to choose the most suitable instrument for your measurements.
Please contact the Responsible Person for any doubts or questions.
Please check Rules for Mass Spectrometry Service
ESI (Bruker Esquire HCT)
The routine (open access, contact the responsible for training) instrument capable of measuring masses in the range 50-3000 m/z. ESI works only if your compound has a permanent charge (e.g. quaternary ammonium compounds, metal complexes) or if it can take a charge from protonation (positive mode), deprotonation (negative mode) or formation of adducts with charged species (usually Na+ or Cl-).
MALDI (Bruker UltrafleXtreme MALDI-TOF)
This instrument is capable of measuring molecules of high molecular weight (1000-500000 m/z) and it is the standard instrument for polymer analysis. The access to this instrument is restraint: MALDI measurements can be requested using the MS Request Form