How to calibrate monitors for ÄKTAdesign systems

How to calibrate monitors

The table below describes how to calibrate the monitors for ÄKTAdesign systems:

Step	Action
1	Select System:Calibrate in the System Control module. Result: The Calibration dialog box is opened.
2	Select a monitor in the Monitor drop-down box and perform the procedures as described in the dialog box.
3	Repeat step 2 for each monitor type.
4	Click the Close button when the calibrations have been made.

How to calibrate a pH monitor

Some ÄKTAdesign systems have a pH monitor to allow online pH measurements. Below is an illustration of the dialog box for pH calibration:

Note:

Calibration can be performed with the electrode either within or outside the flow cell.

Instruction

The table below describes how to calibrate a pH monitor with the electrode mounted in the flow cell:

Step

Action

Attach the first pH reference solution, for example pH 7.0, to Inlet A11 on the system.
Attach the second reference solution, for example pH 4.0, to Inlet B1.

In the System Control module, select Manual:Pump.

Result: The Instructions dialog box is opened.

Select Pump:PumpWash Explorer in the Instructions field.
In the parameters field, select Inlet A11.
Click the Execute button.

Result: The pump and inlet tubing will now be filled with the first reference solution. Wait until the PumpWash is finished before you continue to the next step.

In the Instructions field, Select Pump:Flow.
In the FlowRate box, insert the flow rate that you will use later during your run.
Click the Execute button.

Allow at least 35 ml of reference buffer to pass through the cell, during which time the pH should stabilize.

Select System:Calibrate from the System Control menu.
In the Monitor drop-down box, select pH.

Note:

The Measured value field shows the actual reading according to the previous calibration. This value may be incorrect and does not affect the current calibration.

When the pH is stable, do the following:

Enter the known pH of the reference solution in the field Reference value 1
Click the Read Value 1 button.

Switch to the second reference solution this way:

Select Manual:Pump.
Select the instruction Pump:Gradient
In the Parameters field, set target to 100% B after 0 minutes.
Click the Execute button.
Select the instruction Pump:PumpWashExplorer.
In the Parameters field, set Inlet B1 to ON.
Click the Execute button.

Result: Do not continue to the next step until the PumpWash is finished.

When the pH is stable, do the following:

In the Calibration dialog box, enter the known pH of the reference solution in the field Reference value 2
Click the Read Value 2 button.
Click the Close button.
Click the End button to stop the flow rate.

After the calibration, the values are automatically entered into the Calibrated electrode slope and Asymmetry potential at pH 7 fields.

Note:

If you calibrate with the electrode outside the flow cell, do not remove the electrode from Solution 1 until the Read Value 2 button has become available (when the button text has turned from grey to black).

2005-06-15