A comparison between ion-to-photon and microchannel plate detectors

Abstract

An alternative detector for time-of-flight mass spectrometry, the ion-to-photon detector, detecting light produced when ions impact a surface coated with a fluorescent compound, was compared to a conventional microchannel plate detector. Single ion experiments showed that, for a given energy, the efficiency of the ion-to-photon detector relative to the microchannel plate detector decreases as the molecular mass of the impinging ion increases. This decrease becomes less pronounced for larger ions. Seen as a function of the ion velocity, a linear relationship was found. The conversions into photons and electrons were also compared. It was found that 22 keV ions up to 150 Da produced more photons than secondary electrons. For larger ions at this energy, the opposite was observed.

Principles and Applications of LC-MS/MS for the Quantitative Bioanalysis of Analytes in Various Biological Samples

“…Because the number of ions leaving the mass analyzer at a particular instant is typically quite small, considerable amplification is often necessary to get a signal. Microchannel plate detectors are commonly used in modern commercial instruments (Dubois et al, 1999). In FT-MS and Orbitraps, the detector consists of a pair of metal surfaces within the mass analyzer/ion trap region which the ions only pass near as they oscillate.…”

“…Conventional MS has relied on ionization-based detectors, namely those producing and multiplying secondary electrons associated with particle bombardment of a metal surface; such detectors are restricted to ions having a mass less than 10 6 Da. An ion-to-proton conversion detector (IPD) shows promise for detecting macro-ions (Dubois et al, 1997;Dubois et al, 1999). Photosensitive detectors, relying on laser-indued fluorescence (LIF) or elastic light scattering (ELS), show promise in this area.…”

An introduction to liquid chromatography–mass spectrometry instrumentation applied in plant metabolomic analyses

“…The task of the TDC is to count the amplifi ed signal information it receives into time bins across a mass spectral scan. A typical mass spectral scan for a 4 GHz TDC consists of 20 time bins, which produce an approximately 50 µs scan window (Matsuura et al, 1985;Dubois et al, 1999). Each time the accelerator region pulses the ions, the TDC is initiated (Fig.…”

A fast microchannel plate-scintillator detector for velocity map imaging and imaging mass spectrometry

“…Other organic scintillators have also been investigated for applications in mass spectrometry. For example, Dubois, Zenobi, and co-workers 17,18 used the organic components But-PBD (2-(4-tert-Butylphenyl)-5-(4biphenylyl)-1,3,4-oxidiazole) and BBOT (2,5-bis(5 -tertbutyl-2-benzoxazolyl)thiophene) to build an ion-to-photon conversion detector (IPD). The detector consisted of a glass plate coated with a layer of the organic material and mounted in front of a PMT.…”