There are at least five attributes of a good spectrum: low noise, little or no baseline offset, a flat baseline, peaks on scale, and a lack of spectral artifacts.ДЄn example of a bad spectrum is shown in Figure 1. The higher the quality of the spectrum you are working with, the easier your interpretation job will be. This column will teach you a 12-step program that, if followed, should help you be more successful at interpreting spectra. To successfully interpret infrared spectra one must follow the right process, or else it is easy to be misled. The challenge with interpreting spectra, however, is that with the hundreds of known functional groups that absorb in the mid-infrared and the resultant thousands of peaks, it becomes difficult to figure out what peaks are from what functional groups. Infrared (IR) spectral interpretation is firmly grounded in science as seen in the theory sections in previous installments. The answer to last columnвЂ™s quiz is also disclosed. The process includes knowing how a spectrum was measured, systematically identifying peaks, and the proper use of infrared spectral interpretation aids. The author has developed this 12-step system over many years of interpreting spectra, and finds it gives him the best results.

We wrap up our introduction to the theory of infrared spectral interpretation with a discussion of the correct process to follow when interpreting spectra.

How to read an ftir spectrum