Principles of Fluorescence Spectroscopy

PRINCIPLES OF FLUORESCENCE SPECTROSCOPY 881
Table I.9. Corrected Emission Spectrum of 2-
Aminopyridine a
ν (cm –1 ) I(ν) λ (nm) I(λ) b
20,800 0.010 480.8 0.006
21,500 0.038 465.1 0.024
22,200 0.073 450.5 0.049
23,000 0.133 434.8 0.095
23,800 0.264 420.2 0.202
24,700 0.450 404.9 0.371
25,600 0.745 390.6 0.660
26,600 0.960 375.9 0.918
27,200 1.00 367.7 1.00
27,800 0.939 359.7 0.981
28,900 0.587 346.0 0.663
30,150 0.121 331.7 0.149
31,000 0.033 322.6 0.049
a 10 –5 M in 0.1 N2 SO 4 . From [10] and [11].
b Calculated using I(λ) = I(ν)λ –2 followed by normalization
of the maximum to unity.
(Table I.9 and Figure I.10). Corrected emission spectra have
been reported 10 for phenol and the aromatic amino acids,
phenylalanine, tyrosine and tryptophan (Figure I.11).
6. ADDITIONAL CORRECTED EMISSION
SPECTRA
Corrected spectra as I(ν) versus ν can be found in the compendium
by Berlman. 11 Included in that volume are a number
of UV-emitting species including indole and phenol,
which can be used to obtain corrected emission spectra of
proteins. For convenience Berlman's spectra for phenol and
Figure I.10. Corrected emission spectra of 2-aminopyridine in relative
quanta per wavenumber interval I(ν) and per wavelength interval
I(λ). See Table I.8 for additional details. From [8] and [9].
Figure I.11. Corrected emission spectrum (I(λ)) for phenylalanine
(!), phenol (△), tyrosine (), and tryptophan ("). The areas underneath
the curves are proportional to the quantum yields. Data from
[10].
Figure I.12. Corrected emission spectra of phenol in methanol and
indole in ethanol. From [11].
indole are provided as Figure I.12. Cresyl violet in
methanol has been proposed as a quantum yield and emission
spectral standard for red wavelengths. 12 In methanol at
22°C the quantum yield of cresyl violet is reported to be
0.54, with an emission maximum near 614 nm. The use of
quinine as a standard has occasionally been questioned. 13–16
Additional discussion about corrected emission spectra can
be found in [17–20].
REFERENCES
1. Gardecki JA, Maroncelli M. 1998. Set of secondary emission standards
for calibration of the spectral responsibility in emission spectroscopy.
Appl Spectrosc 52:1179–1189.