Chapter XII Reflectance Spectrophotometry

Publisher Summary The separation and determination of an absorbing substance from microbial material is often impracticable. A measure of concentration may be obtained from reflectance spectrophotometry using a procedure analogous to that of the analysis of transparent media by transmission spectrophotometry. When the bands are widely separated, evaluation of the band intensity, width and shape is a relatively simple matter. The absorption spectra of biological materials exhibit overlapping bands, and measurement of the band characteristics cannot be made separately for each band. An analytical technique that minimizes this difficulty has been used particularly for the estimation of cytochrome in micro-organisms. In the medical field, changes in tissue chemistry produced by disease affects differences in the infrared attenuated total reflectance spectra of the tissues.