Team:DTU-Denmark/Methods/Calibrating Electrodes

From 2013.igem.org

Calibration of electrodes

Calibration of NO and N2O electrodes/probes

  • Cleaning the probes
  1. Prepare 96% ethanol solution
  2. Prepare 0.01M HCl solution
  3. Put both probes in ethanol solution for 1 minute
  4. Put both probes in HCl solution for 1 minute
  5. Rinse with demineralized water
  • Calibration
  1. Make standard solution NO
    1. Make 200 ml solution 1 M NaOH
    2. Make it anoxic by bubbling with N2 for 5 minutes
    3. Make MQ water anoxic
    4. Bubble 5% NO solution through NaOH solution
    5. Convey towards the water flask for 20 minutes
  2. Make standard solution of N2O
    1. Make solution anoxic by bubbling 5 minutes with N2
    2. Flush with N2O for 20 minutes.
  • Procedure
  1. Pure 200 ml of DM minimal medium in the bottle
  2. Adjust the temperature at around 37oC by using a magnetic stirrer
  3. Adjust both of the probes in the lid of the bottle
  4. Connect the electrodes with the microsensors
  5. Make the solution anoxic by bubbling with N2 for 10 minutes
  6. Start by calibrating N2O sensor (the adding points are the concentration of N2O in mg/L)
    1. Add the first point “0” on the sensor
    2. Spike 0.5 ml of N2O in 200 ml and add point “60.35”
    3. Spike 0.5 ml of N2O and add point “120.7”
    4. Spike 0.5 ml of N2O and add point “181.06”
    5. Spike 0.5 ml of N2O and add point “2241.41”
    6. Spike 1 ml of N2O and add point “362.11”
    7. Spike 1 ml of N2O and add point “482.81”
    8. Then apply the calibration for the sensor
  1. Continue by calibrating NO sensor (the adding points are the concentration of NO in mg/L)
    1. Add the first point “0” on the sensor
    2. Spike 1 ml of NO in 200 ml and add point “0.47”
    3. Spike 1 ml of NO and add point “0.94”
    4. Spike 1 ml of NO and add point “1.4”
    5. Spike 1 ml of NO and add point “1.86”
    6. Spike 1 ml of NO and add point “2.31”
    7. Then apply the calibration for the sensor