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8.2.8 Hydrogen Peroxide
This is a direct electrochemical reading of hydrogen peroxide at the enzyme probe. A structure similar in appearance to
an enzyme membrane is used at the probe surface. This membrane contains immobilized nonenzymatic protein to
produce diffusion properties similar to those exhibited by YSI Enzyme Membranes.
The electrochemical reaction, which is common to all YSI Enzyme Sensors, is the following:
H
2
O
2
Platinum anode
2H
+
+ O
2
+ 2e
-
System Buffer
YSI 2357
Calibrator Std
n/a
Linearity Std
n/a
Membrane
YSI 2701
Membrane
Color
Yellow
Detection
Range
3–300 mg/L
Calibration
Point
~30 mg/L
(recommended)
Sample Size
25
µ
L
End Point
30 sec
Typical Working
Life
~21 days
Note: See
Unit Conversion if concentration unit
conversion is required.
Special Considerations:
•
Since hydrogen peroxide is typically used to calibrate the
YSI Blank Membrane, the enzyme
catalase
is a concern.
Catalase destroys hydrogen peroxide. Buffer
pretreatment may be required.
•
If you suspect an electrochemical interference (as
opposed to an enzymatic interference), you may want to
use one channel to
qualitativel
y monitor for an
interference effect.
•
Typical electrochemical interferences include phenols,
mercaptans, hydroxylamine, hydrazine and analines. If
you suspect a particular substance, you may want to
configure one of your probes with a blank membrane and
calibrate it as described above under Hydrogen
Peroxide. Then run your sample and check for activity at
the Blank Membrane. It is not quantitative, but may
provide useful information about your sample.
•
YSI believes that you will be able to measure this analyte
for many applications in the range specified. However,
YSI makes no claims with respect to precision or
linearity. User will need to prepare the calibrator and
linearity standards for your application as YSI does not
currently offer hydrogen peroxide standard solutions.
5
YSI does not currently offer hydrogen peroxide standards.
