Efficient Calibration for in-Situ Measuring L-Glutamic Acid Solution Concentration Via ATR-FTIR

In this presentation, an efficient calibration method is proposed for in-situ measuring the concentration of L-glutamic acid (LGA) solution via ATR-FTIR. We clarify that using the unsaturated zone spectra as commonly practiced for establishing a concentration calibration model may lead to evidently biased measurement of the solution concentration. By comparison on using the spectra of unsaturated and metastable zones for calibrating the concentration of LGA aqueous solution, it is demonstrated that the use of metastable zone spectra to establish a calibration model can guarantee prediction accuracy for the solution concentration via real-time ATR-FTIR monitoring. Experiments under different concentrations and temperatures are performed to verify the efficiency of the proposed calibration method. In addition, it is shown that the proposed calibration model can also be used for nucleation detection, therefore facilitating real-time monitoring of batch cooling crystallization in practice.