What is Ion Mobility Spectrometry ?

[https://en.wikipedia.org/wiki/Ion-mobility_spectrometry]

Why should we do this ?

There are numerous application for IMS and it has the main advantage to work at atmospheric pressure (in constraste with mass spectrometry that requires most of the time 10-3 torr) that would make it compact and affordable.

We see the possibility to make continious monitoring of the bioreactor made by Hackuarium and situated in Cali, Colombia.

Can we do a Ion Mobility Spectrometer our self ?

Main parts of the IMS :

• Desolvation zone : Insert and ionization of sample. Electrospray ionisation (ESI). Advantage : one can insert the liquid sample and ionize it through the same needle. Limitation : 5kV voltage source, 100uL/min flow rate through the needle.

• Shutter : Let the ions pass on command. Three grid Shutter. Advantage : easy to built and to command.

• Drift zone : Acceleration of ions. Made by multiple electrodes connected to different voltages with the aid of a voltage divider. Limitation : 10kV voltage source.

• Detection : Faraday plate. Transconductance amplifier converts the tiny ion current into a reasonable tension. Limitation : The current-to-tension AOP must be with very low bias current, and low noise (hence expensive).

• Monitoring : A/D converter.

Link to full project already made : [https://github.com/bhclowers/OS-IMS]