Biology Reference
In-Depth Information
adsorbed electroactive species is seven to ten times higher than
the original voltammetric signal. Second, the shape of the signal
allows the subtraction as the distance between the current
minimum and maximum and does not require any other baseline
correction.
11.2.3
Single and Double Mode of EVLS
The above-mentioned EVLS procedure corresponds to the sin-
gle mode, and functions eliminating two currents require three
voltammetric curves measured at three different scan rates. When
this elimination procedure is repeated three times using LSV
curves measured at five different scan rates (
v
1
/
4
,
v
1
/
2
,
v
,
v
2
,
v
4
),
for example, 25, 50, 100, 200, and 400 mV/s, respectively, the
double EVLS function E4 is obtained, where
I
d
=
0,
I
k
=
0, and
I
c
=
0.
I
1
/
4
I
1
/
2
I
⎫
⎬
⎫
⎬
f
(
I
)
=
a
1
I
1
/
4
+
a
2
I
1
/
2
+
a
3
I
⎭
⎫
⎬
=
a
1
I
1
/
2
+
+
f
(
I
)
a
2
I
a
3
I
2
double
f
(
I
)
=
a
1
(
a
1
I
1
/
4
+
a
2
I
1
/
2
+
a
3
I
)
+
a
2
(
a
1
I
1
/
2
+
a
2
I
+
a
3
I
2
)
+
a
3
(
a
1
I
+
a
2
I
2
+
a
3
I
4
)
⇓
double
f
(
I
)
=
a
d1
I
1
/
4
+
a
d2
I
1
/
2
+
a
d3
I
+
a
d4
I
2
+
a
d5
I
4
⎭
⎭
⎫
⎬
I
2
f
(
I
)
=
a
1
I
+
a
2
I
2
+
a
3
I
4
⎭
I
4
Equations corresponding to the double elimination functions,
eliminating two current components and conserving one current
component,areshowninTable11.2.Itshouldbenotedthaterrorof
double EVLS is relatively high, and therefore it is necessary to work
carefully with it. On the other hand, a voltammetric signal increases
by more than one order (Fig. 11.2). Moreover, the separation of
overlapped voltammetric signals in the double EVLS mode is much
more successful [23].
