WPI APOLLO 4000, Instruction Manual

Page: 64 / 74

APOLLO 4000
HYDROGEN PEROXIDE DETECTION
World Precision instruments e-
Calibration of the HPO Sensor
Hydrogen Peroxide (H o ) is a very important product in the biological system. the
determination of H o requires an accurate method of calibration. Amperometeric
(electrochemical) determination using the Apollo is a very reliable method to
measure H
o . the Apollo measures the amount of H o oxidized on the surface
of the sensor using a poise voltage of +400 mV. the oxidation of H o at the
sensor surface produces a small current (pA), which is detected by the Apollo.
the amount of current produced is linearly proportional to amount of H
o in the
experiment.
Items required
• Plastic stand with two holes
• one glass vial
• .0mm H
o standard solution (available from WPi)
• 0.0m PBs buffer solution (PBs buffer tablets available from WPi)
note: the multi-port measurement chambers (WPi# NOCHM or # NOCHM-4 ) can
be used as an alternative calibration kit, specifically for use at different temperature
condition. calibration temperatures from 4 - 40°c can be controlled using an
external circulating bath (contact WPi for information).
Calibration Procedure
1.
turn on the instrument Apollo 4000, set all the parameters that are needed
in experiment. select the poise voltage for hydrogen peroxide in the
software.
2.
Add an appropriate volume (e.g.,0 ml) of PBs buffer solution (0.0m) in
glass vial. turn on the stirrer so that the bar is stirring in moderate rate.
3.
remove the sensor from the electrolyte solution in which the tip has been
immersed during storage. immerse the iso-HPo- sensor tip in PBs
buffer solution (0.0m), the sensor tip should be immersed about 0.3-
0.5mm into the solution, and should not be touched by stir bar.
4.
record the current value. if the current is offscale or unstable after a half
hour in solution, it is likely that the membrane has been damaged and
the sleeve needs to be changed (refer to the section on“changing the
sleeve”).