Reference Standards for the Determination of Fluorescence Quantum Yields

1 Reference Standards for the Determination of Fluorescence Quantum Yields 

Fluorescence quantum yield measurements are usually performed on fluid solutions at room temperature. The solvents must be of appropriate purity and suitable for fluorescence measurements it is advisable, however, to verify the absence of spurious emissions due to the solvent itself or to other dissolved species (impurities and/or stabilizers) under the conditions used. 

Finally, the choice of the common excitation wavelength for the sample and reference solutions, corresponding to isoabsorptive points, is of the highest importance for a high quality measurement of the quantum yield. This wavelength should be selected in a region where both absorption curves are not steep, in order to avoid errors related to small differences in the values of X (e.g., because of a slightly different calibration of the employed spectrophotometer and spectrofluo-rimeter) and of the slit widths. Commonly used reference standards for the determination of fluorescence quantum yields are listed in Table 5.3. Other similar tables can be found in [1, 6, 16, 17]. 

In order to facilitate the choice of the reference standard on the basis of the spectral region of interest and the band shape, the fluorescence spectra of the most popular standards are reported in Figs. 5.16, 5.17, 5.18. 

Relative value, using both quinine sulfate and 9,10-diphenylanthracene as reference standards ° Measured with an integrating sphere, using quinine sulfate as a reference standard Aerated solution, with substantial oxygen quenching [19] for other comments, see [15] 

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Table 5.3 Reference standards for the determination of fluorescence quantum yields...

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