Abstract

The existence of isosbestic point(s) in a set of UV-visible spectra is rarely exploited for quantitative or qualitative information despite its interest. Indeed, the presence of isosbestic points means a quality and quantity conservation in the global composition of samples with a given relation between the concentration of absorbing compounds or mixtures of compounds. However, in some cases, for example, when a dilution occurs, no isosbestic point appears. This work shows that a simple operation, called normalization, can reveal the existence of hidden isosbestic point(s) (IP*). This paper first summarizes the required conditions for the presence of isosbestic points. Second, it demonstrates the significance of IP* revealed by normalization. An example of the exploitation of direct or hidden isosbestic points in the environmental field illustrates the interest in and application of the technique.

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The Ultraviolet Absorption Spectra of Protein Solutions1

R. Norman Jones and Hugh J. Creech
J. Opt. Soc. Am. 33(4) 209-218 (1943)

Controlling the transmitted field into a cylindrical cloak’s hidden region

Jeffrey S. McGuirk and Peter J. Collins
Opt. Express 16(22) 17560-17573 (2008)

Far-Ultraviolet Auroral Spectra

H. M. Crosswhite, E. C. Zipf, and Wm. G. Fastie
J. Opt. Soc. Am. 52(6) 643-648 (1962)

Speckle imaging and hidden phase

Gregory C. Dente
Appl. Opt. 39(10) 1480-1485 (2000)