How is infrared spectroscopy used in an industry to find the purity of an ester?

1 Answer
Sep 13, 2016

There's the old way and the new way.

The Old Way

"They" would periodically take an infrared spectrum of the sample and compare it with a spectrum of the pure ester.

Any extraneous peaks would be caused by the presence of impurities.

If the peaks matched those of known impurities, they could use the intensities to calculate the purity of the ester.

The New Way

With the advent of computers and Fourier Transform technology, I suspect that many industries use differential infrared spectroscopy.

The ester probably flows through the machine in a continuous flow process.

A spectrum is obtained periodically, and a stored spectrum of the pure ester is digitally subtracted from that of the sample.

This leaves only a spectrum of the impurities, which can be compared with a stored database of impurities.

The computer identifies the impurities and automatically generates a report on the composition of the ester.