FTIR Spectroscopy vs. HPLC
Can In-line Spectroscopy Eliminate the Need for HPLC Sampling?
Real-time analysis can be challenging with analytical methods dependent upon remote sampling such as HPLC (or GC). Although HPLC and GC are valuable analytical tools, they are performed with the instruments removed from the manufacturing environment, require an additional staff member to accurately pull and deliver samples, and then rely on waiting for laboratory results to be returned.
Alternatively, FTIR spectroscopy is also a powerful technique. Some standard FTIR spectroscopy systems even have the ability to provide real-time analysis through the use of long fibre-optic cables connecting the probe to the instrument. Unfortunately, they are highly sensitive to vibration, known to be difficult and many times impractical to operate in more challenging manufacturing environments.
Is there a more practical solution? Yes. By creating a rugged, vibration-tolerant FTIR spectrometer, an analytical instrument can now be used in line to the manufacturing process and thereby provide continuous analysis in real time. No more need for remote sampling. You can dependably monitor the process at the point of production – as it happens – and no longer wait for the results to come back from the laboratory.
Can we prove this? Yes. We compared the two methods.
FTIR Spectroscopy: Industrial Fermentation Trial
Keit has developed a rugged in-line FTIR spectrometer that can operate in situ. We set out to prove our FTIR technique was just as accurate as HPLC analysis technique as applied to an industrially relevant process. We ran our IRmadillo™ FTIR spectrometer to measure a fermentation and hydrolysis process and at the same time pulled samples for HPLC analysis to compare the two. Results? The IRmadillo™ FTIR spectrometer excelled at providing continuous process monitoring. It did so with equivalence to off-line HPLC and thus we believe it can remove the requirement to perform periodic sampling during a commercial production run, with significant efficiency, quality and cost benefits.
Results: Keit FTIR Vs. HPLC
In Figure 1 below are results of the Keit IRmadillo™ FTIR spectrometer versus HPLC in monitoring an industrial fermentation process. The fermentation consumes the feedstock to produce two intermediates which are converted into the key product, a secondary product and a by-product. By combining the spectrometer with a PLS model it is possible to monitor all six compounds in real time with concentrations of 0.1 to 50 g / L.
Further Industrial Applications
Through trials with several industrial biotech companies, Keit has demonstrated an ability to quantify, down to 0.1 g/L (100 ppm), a wide range of organic species from sugars to alcohols, acids, and even biomass.
Figure 1: Plot of predicted values for analytes from PLS model of Keit IRmadillo™ FTIR data with overlay of HPLC reference