Ultra-high resolution for mass spectrometric analysis of complex and low-abundance mixtures – the emergence of FTICR-MS as an essential analytical tool

Abstract

The role of high resolution in mass spectrometric analysisThe development of applications of mass spectrometry to chemical analysis has followed several paths, such as invention of new techniques for ionization, for acquisition of additional information concerning the relationship between fragment ions in the spectrum (tandem mass spectrometry), and for on-line coupling of a mass spectrometer to separatory techniques for real-time mixture analysis. Other features of any analytical instrument, such as sensitivity and detection limits, spectral acquisition rate, m/z range, etc., have, in mass spectrometry, often been driven by the need to match the low sample levels and higher resolution which have resulted from the introduction of capillary-based chromatographic methods.This article, however, is concerned with another figure-of-merit, the resolving power of the mass spectrometer itself. Historically, the need for higher resolving power was driven by investigations into isotopic compositions of the elements after Aston's landmark discoveries. Magnetic sector instruments were the dominant technology, and the invention of the double-focusing principle enabled simultaneous achievement of large increases in sensitivity and resolving power, counter-intuitive for a dispersion analyzer. The desire to detect and measure extremely low levels of rare isotopes, the mass spectral peaks of which were adjacent to those of much more abundant isotopes, required high resolving power, defined in terms of peak widths near the base of the peaks, to achieve the required "abundance sensitivity" for the rare

Reduced levels of hydroxylated, polyunsaturated ultra long-chain fatty acids in the serum of colorectal cancer patients: implications for early screening and detection

“…Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) is based upon the principle that charged particles exhibit cyclotron motion in a magnetic field, where the spin frequency is proportional the mass [26]. FTICR-MS is known for its high resolving power and capability of detecting ions with mass accuracy below 1 part per million (ppm).…”

A global reorganization of the metabolome in Arabidopsis during cold acclimation is revealed by metabolic fingerprinting

“…Although, traditionally, gas chromatography-mass spectrometry (GC-MS) or liquid chromatography-mass spectrometry (LC-MS) has been used to detect metabolites in plant tissues (Fiehn et al 2000, Roessner et al 2001, Sumner et al 2003, Fourier transform ion cyclotron mass spectrometry (FTMS) represents another platform for metabolome analysis in which crude plant extracts may be introduced by means of direct injection without prior separation of metabolites by chromatography (Pinto et al 2002, Goodenowe 2003, Brown et al 2005). This technology is becoming increasingly popular for metabolome studies (Aharoni et al 2002, Mougous et al 2002, Goodenowe 2003, Hirai et al 2004, Murch et al 2004, Brown et al 2005.…”

Utility of three types of mass spectrometers for determining elemental compositions of ions formed from chromatographically separated compounds

“…When FTICR mass spectrometry is coupled with chromatographic techniques, it is usually employed to study large biomolecules or pharmaceuticals 28–33. For FTICR mass spectrometers, the stability of the ion cloud for each exact mass depends on the number of ions present 29.…”