400
250 300
Excitation (nm)
350 400 450
250 300
Excitation (nm)
350 400 450
450
350
300
250
Excitation (nm)
300
400
500
400
450
350
300
250
300
400
500
Emission (nm)
Excitation (nm)
Emission (nm)
0
10
5
0
2
Molar fluorescence (nm
–1
M
–1
C)
Molar fluorescence (nm
–1
M
–1
C)
4
300
400
Emission (nm)
500
300
400
Emission (nm)
500
H 3 C
CH 3
CH 3
O
O
O
O
OH
OH
OH
OH
O
Syringic Acid
Vanillic Acid
5
× 10
4
4
3
2
1
0
10
× 10
4
8
6
4
12
0
× 10
4
× 10
4
Plate 14. Molar fluorescence properties of Syringic (Sigma S 6881) and vanillic acid (Aldrich
H3,600–1) in MilliQ water at room temperature. (Stedmon, unpublished data.)