Ignite Academic Theater Presentation
Microreactor Based Online Reaction Monitoring Using Mass Spectrometry for Structural and Elemental Measurements
Monday, February 5
1:00 PM - 1:15 PM
Location: Exhibition Theater
The monitoring of chemical reactions is an important issue in chemical and pharmaceutical engineering especially in quality control and in the development of new reactions such as catalyst based reactions. The qualitative and quantitative analysis of reactants and resulting products is typically performed using proprietary online measurement systems designed for a special application.
The development of a flexible online reaction monitoring system includes a suitable sampling procedure and sample supply into the analyzer. In detail, an effective coupling system between the reaction system and the measurement system is required. Optical measurement techniques are often used, but also mass spectrometric analyzers are applied due to their higher selectivity. In addition, a user-friendly software for controlling the reaction system, the sample introduction and subsequent measurements is required.
A mobile online reaction monitoring system was developed for a flexible coupling to different measurement systems for elemental (inductively coupled plasma mass spectrometry, ICP-MS) and structural (electrospray ionization mass spectrometry, ESI-MS) analysis to determine the amount of chemical precursors, the resulting reaction products and internal standard substances and their elemental composition at any stage of the reaction. The chemical reactions take place in a tempered continuous flow microreactor. For monitoring several reaction stages, the flow rate in the microreactor can be varied to realize various residence times of the reactants in the reactor. To adapt the concentration of the solutions leaving the reactor output to the working range of the mass spectrometer an online dilution module was integrated. This enables the dilution with ratios from 1:50 up to 1:1,000. The coupling between the reaction system and the ICP-MS is realized using a direct sample stream with a flow rate compensation. The coupling to the ESI-MS is realized using a multiport valve and a carrier solvent flow. In this study, a time-of-flight mass spectrometer was used. The performance and the limitations of the online reaction system were determined using both, well-known standard solutions and a real chemical reaction.
The online reaction monitoring system presented facilitates a detailed insight into the kinetics of chemical reactions. Application examples are the transformation of a precatalyst into its active species, the product/educt ratio, or the appearance of transient intermediates. The online reaction monitoring system enables a sampling without discontinuing the reaction process, fast elemental and structural analysis, and an online optimization of chemical processes. The control software provides the adjustment of reaction, sampling and measurement parameters as well as the system and process control. A mobile system structure facilitates the connection to the wished measurement instrument. This provides a high flexibility and enhances the methodological scope of the system presented. This academic research project will be directly transferrable to the pharmaceutical and other chemical industries at the completion of the project.