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RU 1088

The ConDuct Electrode Improves Ion Transmission into a Mass Spectrometer

The sensitivity, resolution, and analytical speed of mass spectrometers are greatly affected by the efficiency of ion transfer between the atmosphere and the vacLuum. As the efficiency of ion transfer increases, loss of ions produced from the sample of interest is minimized resulting in a more sensitive and informative analysis by the instrument.

Scientists at The Rockefeller University have developed a new type of ion inlet electrode for electrospray ionization mass spectrometers, which can transmit into the vacuum nearly 100% of an electrospray ion current produced at atmospheric pressure. This electrode, aptly named ConDuct, uses a conductive tube containing a slowly diverging channel that increases its diameter from its entrance towards its exit. This slight divergence (generally in the range of one to a few degrees) produces a laser-like focused gaseous ionic beam with very low angular dispersion that travels long distances in vacuum.  The ConDuct has been used to modify commercial ion trap instruments and was shown to transmit at least 400 times more ions than Thermo LCQ DECA XP atmosphere-to-vacuum interface and 6-17 times more than the commercial interface in the Thermo Velos Orbitrap and the Q Exactive mass spectrometers. The ConDuct exhibits an improved ion transmission efficiency and signal-to-noise ratio compared to similar commercial interfaces.

Area of Application

Mass spectrometry instrumentation.

Stage of Development

Prototype developed and tested.

Lead Inventor

Dr. Brian Chait

Patent Information and References

  • U.S 9,048,079
  • Krutchinsky A.N. et al, Maximizing Ion Transmission from Atmospheric Pressure into the Vacuum of Mass Spectrometers with a Novel Electrospray Interface; J.Am.Soc. Mass Spectrom. (January 2015).
  • Krutchinsky A.N. et al, Optimizing Electrospray Interfaces Using Slowly Diverging Conical Duct (ConDuct) Electrodes; J.Am.Soc. Mass Spectrom. (January 2015).

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