On-line analysis of a continuous-flow ozonolysis reaction using Raman spectroscopy

We describe the use of an on-line Raman analyzer to quantitatively track the levels of trans-stilbene, benzaldehyde, and alpha-metboxybenzyl hydroperoxide in a continuous flow ozonolysis reactor. Quantitative analysis is carried out using spectral stripping in order to overcome baseline artifacts inherent in simple peak area determinations and to incorporate prior knowledge into the analytical model. The performance of spectral stripping is compared to partial least squares (PLS) analysis. The effect of two process variables, feed flow rate and ozone concentration, are also explored. Finally, the benefit of utilizing an on-line technique is illustrated by demonstrating the bias introduced by sampling for off-line analysis.