Acquiring this novel UV ionization source would be of major interest for our MS platforms. Ionization occurs with both a concentric dielectric barrier discharge and a UV light. The soft ionization mechanism of SICRIT® is a huge advantage in terms of identification. Indeed, combining three simultaneous ionization mechanisms significantly expands the range of detectable analytes, covering polar and non-polar components. Those mechanisms are ESI-like, APCI-like and finally PI-like with a UV light that can ionize the molecule directly or via charge transfer. The ambient character of the ionization source allows to analyze solid, liquid or gaseous samples in room air without sample preparation. The unique shape of the cold plasma enables a very soft ionization and avoids fragmentation. The SICRIT® source provides the possibility to perform screening with or without quantification, and can easily be coupled to LC/MS and more precisely to Thermofisher OT instruments.
The Triversa NanoMate® nanochip-based ESI uses chips consisting of 400 nozzles. The electrical field created between the conductive tips and the nano-electrospray nozzle results in a highly efficient ionization and long lasting, stable sprays from µL of sample volume. The Triversa NanoMate® allows high throughput infusion experiments for many different types of desalted analytes for applications ranging from routine HRMS measurements to shotgun lipidomics, non-covalent interaction studies (NCI), peptide and protein as well as oligonucleotide characterization. The very low spraying flowrates prevents contamination of the instrument ion optics, zero sample-to-sample carryover due to the one tip-one nozzle workflow per sample, while allowing the analysis of sample volumes as low as 1 µL. In addition to the chip-based direct infusion capabilities, the Liquid Extraction Surface Analysis (LESA®) technology offers to the EPFL researchers community new techniques of surface analyses. Its unique surface extraction via a liquid droplet held in suspension (liquid junction) allows a novel approach for spatially resolved analysis of surfaces. Successful LESA experiments can be achieved from a wide variety of surfaces including: animal whole body or organ sections, polymers, medical devices, bacteria grown on agar plates, and plant materials such as roots, leaves and peels. The pipetting accuracy of the TriVersa NanoMate enables high sensitivity experiments with a spatial resolution of 1mm on target.
Exploris 240 although being very versatile delivers a resolution performance restricted to 240 k at m/z 200, which might not be sufficient to resolve fine isotopic structures. At the same time, ion motion on such benchtop Orbitrap has proved to be sufficiently coherent over longer data acquisition periods to achieve an even higher resolution. Due to their application in diverse fields, for molecules of very broad mass ranges, and by operators of very different expertise and knowledge, Orbitrap instruments are greatly simplified by the manufacturer (Thermo Fisher Scientific). As a result, these “push-a-button” instruments underperform compared to what they can deliver based on their overall design and potential. Luckily, it is possible to “unlock” these higher-performing options of these instruments and increase flexibility of their implementation in various applications. One way to accomplish this “upgrade” is to acquire the unprocessed time-domain signals generated by these instruments in parallel with the built-in data acquisition system. As a result, the end-user may (i) gain access to the unprocessed time-domain data (transients); (ii) increase quality of the unprocessed data making it suitable for enhanced quality of Fourier transformation (e.g., mass spectra representation in absorption mode rather than in the enhanced FT mode); and (iii) extend the period (length) of the acquired unprocessed time-domain data. Upon transformation of time-domain data into mass spectra, these advantages translate into improved analytical characteristics of the Orbitrap platform, such as:
- higher obtainable resolution
- higher mass accuracy,
- higher sensitivity and dynamic range
In turn, that allows to improve the performance of the routine applications as well as to enable new applications, not possible with the commercial unmodified instrument. The latter includes such capabilities as isotopic fine structure analysis for macromolecules in a wide mass range (and thus more confident elemental analysis of macromolecules) and higher sequence coverage in top-down analysis of proteins and protein complexes (including monoclonal antibodies and antibody-drug conjugates). Access to the unprocessed time-domain data (transients) also allows to apply novel methods of signal processing, such as the recently implemented individual ion mass spectrometry (I2MS), which is based on processing and analysis of each transient separately. The I2MS application is in the analysis of very complex proteoform mixtures, which otherwise remain unresolved because of the space charge effect in the Orbitraps.
Hardware and software solutions offered by Spectroswiss include a high-performance data acquisition system, FTMS Booster X2, and advanced data processing software, Peak-by-Peak. Acquisition of the FTMS Booster X2 system will open an access to the unprocessed time-domain data and thus will unlock the powerful workflows of data processing offered by the expert version of Peak-by-Peak. The latter includes the I2MS workflow and the 2D (vertical and horizontal) averaging of data from a number of technical replicates. The 2D data averaging increases sensitivity and quantitative accuracy in the analysis of complex molecular mixtures, as has been already demonstrated for top-down and middle-down analysis of monoclonal antibodies and trace-level analysis of organic pollutants. Finally, ability to access and re-process the unprocessed time-domain data allows to also shorten the processed transient length to the periods not provided by the commercial solution. As a result, a clear benefit has been observed for the analysis of complex protein mixtures, particularly antibody-drug conjugates. For the latter, this enabling feature allowed to estimate the drug-antibody ratio, not achievable with the commercial unmodified instrument.
This FTMS Booster X2 can alternatively by used on Q Exactive HF or Exploris 240 Orbitraps, depending on requests and applications.