Reaction Monitoring

The ExpressRT™-100 system incorporates a novel sampling probe designed to prevent sample line blockage in heterogeneous mixtures.

Chemical process development and optimization require quality analytical data taken over the course of a reaction. With integrated reaction sampling and chromatography, the ExpressRT-100 system allows for continuous unattended monitoring of your chemical process.

Not all reactions are performed using homogenous, particle-free solutions. Obviously, automated sampling and the subsequent analysis of reaction mixtures containing small particles present a challenge to the accuracy and precision of online reaction monitoring. The ExpressRT-100 system incorporates a novel sampling probe designed to prevent these potential problems from occurring. A filter is located at the end of the sampling probe where it can trap particulate matter, preventing it from traveling through the sampling line where it would interfere with quenching, dilution and analysis of the reaction samples. Filter materials include 316 stainless steel, PTFE, Nylon, cellulose acetate and paper with pore sizes ranging from 0.2 -0.5μm.

An experiment was performed to test the effectiveness and capacity of the filter. Carbon black was added to a solution of methanol containing two analytes. This solution was repetitively sampled and each sample chromatographically analyzed. Samples were taken over a period of four days and the chromatographic results compared to determine to what extent, if any, the quantitative precision was affected by the accumulation of carbon black particles in the system.

Read the Application Note in its entirety.

 

Real-time monitoring of a chiral reaction by microflow liquid chromatography: Enantiomeric conversion in process scale reaction can now be monitored in real-time using the Microflow ExpressRT™-100 system.

Existing on-line reaction monitoring techniques, like IR, cannot distinguish between enantiomers. The racemization of an enantiomerically pure indanol can be accomplished using Shvo's catalyst, a diruthenium complex. This is an important step in dynamic kinetic resolutions, and is required to increase theoretical yield from 50 to 100% for the product of a highly enantioselective catalytic reaction. Monitoring the racemization of indanol requires a chiral analysis. With integrated reaction sampling and chiral chromatography, the ExpressRT-100 system allows for continuous unattended monitoring and chiral analysis of this process.

Real-time reaction data was generated and saved over 22 hours. The three-fold dilution performed by the sampler allowed direct injection of diluted sample from the reaction vessel onto the column. High performance Microflow chromatography allowed for a chiral analysis to be performed continuously and in real-time. Total sample volume used for analysis was less than 2μL of the reaction mixture volume (< 1%).

The ability to do real-time monitoring of chiral components during a reaction has been achieved with the ExpressRT-100. Spectroscopic monitoring of this reaction would not be able to differentiate the two enantiomers. If the side-product is closely related to the indanol compound, spectroscopic data might also be unable to differentiate this unknown from the indanol racemate.

Read the Application Note in its entirety.