Geoscience Reference
In-Depth Information
Table 3.1.
Nomenclatures for fluorophores in natural waters, showing chemical
component, position of peak fluorescence (excitation/emission maximum in nm),
peak name from literature sources, dual peak component name, and environmental
source of the material
Component ex/em
Peak name
Dual peak
component name
Source
Tyrosine-likeprotein-like
230/305
A
B
Autochthonous,
resembles tyrosine
but may be free or
combined amino acids
275/305
B
1
,8
3
, 6
4
,Y
5
,P2
6
,P5
6
Tryptophan-like protein-like
Autochthonous
230/340
A
T
A
4
275/340
T
1
, 7
3
, S
5
, P6
6
, P7
6
Unknown
Autochthonous?
280/370
N
1
Humic-like M
240/350-400
A
M
5
2
, 6
3
, 3
3
, 2
4
Autochthonous,
microbial
290-310/370-420
M
1
,3
4
, P1
6
,
β
5
Humic-like C
260/400-460
A
c
, A
1
, 1
2
, 1
3
,
α
5
Humic-like C,
4
2
, 4
3
, P8
6
Humic, terrestrial,
allochthonous
320-365/420-470
C
1
,5
3
,5
4
,
α
5
Humic-like C+
Humic, terrestrial,
allochthonous
250/470-504
3
2
, 2
3
, 1
4
, 7
4
, P3
6
385-420/470-504
Pigment-like
Phytoplankton
398/660
P
1
Photobleached
Autochthonous
230/275-350
H, P4
6
Note
: Dual peak component names arise from PARAFAC models in which components have more
than one peak.
References:
1
Coble et al. (
1998
);
2
Stedmon et al. (
2003
);
3
Stedmon and Markager (2005);
4
Stedmon
and Markager (2005a);
5
Parlanti et al. (2000);
6
Murphy et al. (2008).
In samples containing only humic substances, two peaks are observed, one from exci-
tation around 260 nm (peak A
C,
formerly peak A), and one from excitation around 340 nm
(peak C). Peak C shows elongated contours that result from a shift toward longer wave-
length emission as excitation wavelength increases. This fluorescence response is typical
