Simultaneous Online Monitoring of Multiple Reactions Using a Miniature Mass Spectrometer

Abstract

Advances in chemical sampling using miniature mass spectrometer technology are used to monitor slow reactions at a frequency of ca. 180 h (on the Mini 12) with no sample carryover and with inline derivatization in the case of poorly ionizing compounds. Moreover, we demonstrate high reproducibility with a relative error of less than 10% for major components. Monitoring is enabled using a continuous-flow nanoelectrospray (CF-nESI) probe contained in a custom-built 3D-printed rotary holder. The holder position is automatically set using a stepper motor controlled by a microcontroller. Reaction progress of up to six reactions, including hydrazone formation and Katritzky transamination, can be monitored simultaneously without carryover for several hours.

Leveraging 3D printing to enhance mass spectrometry: A review

“…electrodes or tubing) are assembled and aligned. Similarly, a rotary holder for nanoESI emitters was published that allows the monitoring of different reactions running in parallel, by continuously changing the spray tip in front of the MS [98]. In addition to the incorporation of non-printed elements, this shows how easily 3D printing allows the customization of the setup to increase its functionality in a straightforward and user-friendly manner.…”

“…At the same time, such unconnected interfaces suffer from (i) reduced positional reproducibility, (ii) the necessity for more bulky setups in front of the instrument, and (iii) generally a more open interface, which is susceptible to (changes in) ambient conditions, particularly turbulent air flow. An interesting approach in this category has been to employ a 3D-printed rotary holder for nanoESI, which is a good example of how the customizability of 3D-printed interfaces greatly improves the flexibility and system integration of an otherwise complex experimental setup [102].…”

A Review of Portable High-Performance Liquid Chromatography: the Future of the Field?

“…The developments of miniature mass spectrometers are proceeding quickly and highlight the potential for a miniaturised hybrid instrument based on MS and LC [112][113][114][115][116][117][118][119][120][121]. In contrast to UV-Vis, mass spectrometry possesses the ability to provide a significant amount of quantitative and qualitative information free from complex derivatisation protocols.…”

Simultaneous self-optimisation of yield and purity through successive combination of inline FT-IR spectroscopy and online mass spectrometry in flow reactions

“…In combination with online analysis, real-time reaction monitoring becomes possible, where intermediates and byproducts can be observed as well [9]. In particular, inline FT-IR spectroscopy and online mass spectrometry constitute promising analysis techniques that enable rapid quantification of reactants (analysis duration <1 min) [24,[36][37][38][39][40][41][42][43][44][45][46][47][48][49].…”