Image Current Spectrometry
Mass spectrometry is a powerful technique with an enormous market. The latter spans from materials science, to life sciences, geoscience, cultural heritage, as well as industrial processes. For more advanced "operando" spectroscopy, such as that in connection chemical kinetics and catalysis using ultrafast lasers and/or synchrotron beamlines, mass spectrometry has remained at the margin. The reason is related to a relatively slow signal acquisition process in MS which is not acceptable with pulses of a few tens of a femtosecond. This aspect is bottleneck also in the case of low / ultralow sample amounts, e.g. personalized medicine with frequent micro/nano-biosampling, forensic, ore-bearing fluid inclusions, quasi non-destructive cultural heritage diagnostics and/or valuable objectry such as jewels.
A hollow core toroidal (HCT) coil picks up an image current of electrons and/or negative/positive ions passing inside it. This permits to put this as a passive antenna for realtime online full-range mass spectrometry. Full range means concomitant negative and positive mode as well as oxidation state by looking at the electron binding energies. This is a substantial advancement with respect to a classical head-on impact on an ion-beam-killing detector. Further, and above all, the induction signal is all the more sensitive, all the faster (or ultrafast) the target (electron's or ion's) current is. It is a high-pass dif-ferentiator. With that it is blind to DC "background" signals, to the benefit of the signal-to-noise ratio.
The open geometry of the detector, which does not intercept and kills the analytical signal (electrons, ions) permits to stack it inline with an excitation probe. For instance a laser pulse for microanalysis can pass inside the HCT coil to irradiate a target material. The generated electrons and/or ions are thus measured with unprecedented proximity to the sample. A proprietary data reduction procedure is used to extract the spectroscopic information. The technique is available for licensing.