at which the total energy emitted by a sample as heat does not change upon a chemical reaction in or a physical change of the sample. Its position depends on the experimental conditions.
The spectral differences between the isosbestic
points and the iso-optoacoustic points are the result of the non-linear relationship between the molar absorption coefficient
and the photoacoustic signal.
PAC, 2007, 79, 293
(Glossary of terms used in photochemistry, 3rd edition (IUPAC Recommendations 2006))
on page 358
IUPAC. Compendium of Chemical Terminology, 2nd ed. (the "Gold Book"). Compiled by A. D. McNaught and A. Wilkinson. Blackwell Scientific Publications, Oxford (1997). XML on-line corrected version: http://goldbook.iupac.org (2006-) created by M. Nic, J. Jirat, B. Kosata; updates compiled by A. Jenkins. ISBN 0-9678550-9-8. doi:10.1351/goldbook