Online coupling system and control software for reaction monitoring using microreactors and ESI-MS

In chemical engineering the monitoring of chemical reactions as well as the qualitative and quantitative determination of reactants and resulting products is generally performed by online analysis systems. The realization of a suitable sampling procedure and a subsequent supply of the sample into the analyzer are the most important tasks. A real-time reaction monitoring with a high selectivity is charaterized by an existing time difference and sample disruption between the sampling and the analysis process. Therefore, the development of effective coupling systems to sensitive analyzers is an important task. Furthermore, a suitable software for controlling the reaction system and the sample introduction for subsequent measurements is necessary. In this study, a mobile online reaction monitoring system was developed using tempered continuous flow microreactors which are directly coupled to a high resolution time-of-flight mass spectrometer with electrospray ionization (ESI-MS), which enables the determination of the amount of chemical precursors, the resulting reaction products and internal standard substances at any stage of the reaction. This facilitates a detailed insight into the reaction kinetic, for example the transformation of a pre-catalyst into its active species, the product/educt ratio or the appearance of transient intermediates. The monitoring system presented enables sampling without discontinuing the process, fast analysis and online optimization of chemical processes.