High resolution mass spectrometry (HRMS) analysis in the laboratory

First of all, high-resolution mass spectrometers (high-resolution mass spectrometer, HRMS) with analyzers capable of accessing the exact mass such as the time-of-flight mass spectrometer (time of flight, TOF) or Orbitrap are used to quantify organic contaminants. The performance of analyzers is compared by their resolving power, which is defined by the ability to provide signals that can be distinguished for two peaks with nearby masses.

The ability to distinguish ions of different elemental composition with very close molecular masses is therefore determined by resolving power. As a result, high resolving powers are necessary to distinguish peaks with very close masses. A mass spectrometer is considered high resolution if its resolving power RP > 10,000 (FWHM at m/z 200). While the most efficient mass spectrometers are capable of achieving a resolving power of around 1,000 (FWHM at m/z 200), a TOF can reach a resolving power of 60,000 (FWHM at m/z 200) and an instrument equipped with an Orbitrap analyzer can achieve a resolving power of up to 600,000 (FWHM at m/z 200).

Thus, HRMS enables precise measurement of molecular masses or monoisotopic masses.