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Denoting the wavelength of light at which two related compounds have identical extinction coefficients; for example, the wavelength at which the absorption spectra of hemoglobin and oxyhemoglobin cross is their isosbestic point. Spectrophotometry at that wavelength measures total concentration of hemoglobin, regardless of the extent to which it might be oxygenated.
[Ger. isosbestisch, fr. G. isos, equal, + sbestos, extinguished]
References in periodicals archive ?
The isosbestic point 230 nm was found to be satisfactory (Fig.
The validated LC method was found to be accurate and applicable for the simultaneous determination of citalopram (Pramcit 20 mg) with piroxicam (Feldene 10 mg), celecoxib (Celbex 100 mg) and diclofenac sodium (Dicloran 50 mg) in commercial formulations showing good separation with high resolution for all the analytes at the isosbestic point.
All the three redox pairs have isosbestic points at 230-240 nm suggesting a minimal interference with the robust signal of conjugated dienes.
Elucidation of a photoproduct was shown through an isosbestic point on UV-vis and through the absorhance of a photoproduct peak on the HPLC plots.
The retina is illuminated through the pupil, preferably at isosbestic points for oxy- and deoxyhemoglobin, using several discrete visible/NIR light bands while the reflected light from vessels overlying the optic disk is analyzed.
The isosbestic point 158 may, presumably, be due to equal increase of DNA fragments by the probable DNA damage with the increasing in concentration of the compound- DNA complex.
6), we scanned the excitation spectra of the coproporphyrin calibrator and the real fecal samples from 340 to 450 nm, while monitoring the emission at 668 nm, the emission isosbestic point for coproporphyrin and protoporphyrin.
The maximum absorbance is affected by temperature; however, temperature dependency can be avoided by making the absorbance measurements at a temperature isosbestic point (near 1000 nm).
One chooses a combination of absorption maxima and isosbestic points, with a total number of wavelengths equal to the number of components of interest.