Definition of isosbestic point in English:

isosbestic point

Pronunciation /ˌīsəsˈbestik ˌpoint/ /ˌaɪsəsˈbɛstɪk ˌpɔɪnt/


  • A wavelength at which the absorption of light by a mixed solution remains constant as the equilibrium between the components in the solution changes.

    • ‘Once the absorptivities of the component species become dependent on the external variables, isosbestic points do not occur.’
    • ‘On the contrary, for FP the absence of isosbestic points is indicative of parallel or consecutive reaction channels leading to more than one photoproduct.’
    • ‘The difference spectrum has an isosbestic point at 538 nm, maximum at 500 run and minimum at 586 nm.’
    • ‘The isosbestic point of the transition is at 404 nm.’
    • ‘This is supported by the finding that the two bands exhibit an isosbestic point, if the spectra are corrected for their temperature dependence.’


Early 20th century isosbestic from iso-‘equal’ + Greek sbestos ‘extinguished’ (from sbennunai ‘quench’) + -ic.


isosbestic point

/ˌīsəsˈbestik ˌpoint/ /ˌaɪsəsˈbɛstɪk ˌpɔɪnt/