Biology Reference
In-Depth Information
In this context, MV Pchl(ide) (E451F625) refers to the magnitude of the Soret
excitation maximum of authentic MV Pchl(ide) at 451 nm, when its Soret excitation
spectrum is recorded at an emission wavelength of 625 nm, etc. . . .
The mean “
k”
values of five determinations for the MV and DV Pchl(ide) pair
amounted to
k
5
¼
0.004;
k
6
¼
0.07;
k
7 ¼
0.902
0.030;
k
8
0.063
1.100
¼
1.000. The “
K”
values were calculated from Eqs. (
3.39
) and amounted
15.68
to
K
3
¼
0.942. By substituting for the values of
k
6
,k
8
,K
3
and
K
4
in
Eqs. (
3.53
) and (
3.54
) and by further reduction of the substituted equations, the
latter transform into
0.943 and
K
4
¼
MV Pchl
ð
ide
Þð
E437F625
Þ¼
1
:
060
ð
E437F625
Þ
0
:
964
ð
E451F625
Þ
(3.55a)
DV Pchl
ð
ide
Þð
E451F625
Þ¼
1
:
061
ð
E451F625
Þ
0
:
068
ð
E437F625
Þ
(3.56)
3.6.3 Calculation of Small Proportions of MV
Protochlorophyll(ide) in the Presence of Much
Larger Proportions of DV Protochlorophyll(ide)
in the Absence of Interference by Other Tetrapyrroles
To calculate small proportions of MV Pchl(ide) (
<
5 %) in the presence of larger
proportions of DV Pchl(ide) (
95 %), the Soret excitation spectrum of the MV and
DV Pchl(ide) mixture is best recorded at 618 nm. This emission wavelength is at the
short-wavelength tail of the MV Pchl(ide) emission band. Because of slight
differences in the overlap of the MV and DV Pchl(ide) emission bands, the
detectability of small amounts of MV Pchlide in the presence of much larger
amounts of DV Pchlide at this emission wavelength is improved considerably.
Under these circumstances, the (
E
437
F
625) and (E451F625) Soret excitation
amplitudes in Eqs. (
3.53
), (
3.54
) and (3.55), are replaced by (E436F618) and
(E450F618) Soret excitation values. As a consequence, Eqs. (
3.53
) and (
3.54
) are
transformed into
>
MV Pchl
ð
ide
Þð
E436F618
Þ¼
1
:
023
ð
E436F618
Þ
0
:
843
ð
E450F618
Þ
(3.57)
DV Pchl
ð
ide
Þð
E450F618
Þ¼
1
:
023
ð
E450F618
Þ
0
:
029
ð
E436F618
Þ
(3.58)
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