Run Autotune (LC/MS)
Autotune is an automated tuning program that adjusts the MS for good performance over the entire mass range. Autotune is primarily concerned with finding the correct settings for the parameters that control the transmission, filtering, and detection of ions. It is accomplished by introducing a calibrant into the MS and generating ions. Using these ions, the tune parameters are then adjusted to achieve sensitivity, resolution, and mass assignment goals.
Only some sources can be used to run autotune. If you have another source installed, you need to change to a supported source before you can autotune.
For the LC/MSD iQ, the supported Autotune source is the ESI source.
Tune source settings
Parameter | AJS | ESI | APCI | MMI (APCI + ESI) |
|---|---|---|---|---|
Gas temp (°C) | 300 | 300 | 325 | 325 |
Gas flow (L/min) | 7 | 7 | 5 | 5 |
Nebulizer (psi) | 15 | 15 | 60 | 60 |
Sheath gas heater | 200 | n/a | n/a | n/a |
Sheath gas flow (L/min) | 11 | n/a | n/a | n/a |
Vaporizer (°C) | n/an/a | n/a | 200 | 200 |
Capillary | 4000 | 4000 | 2500 | 2500 |
Nozzle | 1500 | n/a | n/a | 2000 |
APCI needle | n/a | n/a | 4 (pos), -10 (neg) | 4 (pos), -10 (neg) |
Frequent tuning is not required for normal operation. Once tuned, the MS is very stable. Tuning is generally not needed more often than monthly, or at most weekly. If you suspect problems related to tuning, Run Checktune to confirm that the MS is out of adjustment before you retune it.
Make sure that you wait for equilibration before running Autotune. If Autotune is Out of Tolerance, please contact Agilent.
Run an Autotune
To run an Autotune, you must have the Manual control (only when instrument is idle) permission and either the MS autotune or MS autotune and manual tuning permission.
Click Method.
In the Acquisition Method window in the navigation pane, click Instrument Setup > SQ.
In the navigation pane, select Tune > Autotune.
If needed, click Take. In this image, Take is already selected.
Click
Tune control to lock the instrument for tuning.Click
Run Autotune.Click
Tune control to unlock the instrument after you finish tuning.
Autotune toolbar
In the Autotune section, the following options are available:
| Click to lock control of the instrument for tuning. This button is only available when the instrument is unlocked. |
| Click to unlock control of the instrument. This button is only available when the instrument is locked for tuning. |
| Click to generate a detailed tune report. |
| Click to open the Schedule Tune dialog. |
Show description | Select to display the Description column in the tune table. The descriptions match the descriptions from the tune configuration table, including any customizations. |
| Click to start an Autotune. When clicked, the Estimate total run time is displayed. The estimated run time is based on previous autotune records. |
| Click to stop the tuning process. |
| Click the save the contents in the Tune status window as a .txt file. |
Autotune table
The following table describes the columns in the tune table:
On | The Standard Quadrupole is automatically selected and cannot be unselected. |
Instrument mode | The name of the instrument mode. |
Polarity | The polarity chosen for this instrument in the Configure Tune section (±, + or -). |
Tune status | The status of the tune (Running, Reading, Expiring soon, Expired, or Error). |
Last tuned | The date the last autotune was performed. |
Expires on | The recommended date that the next autotune should be performed to maintain optimum performance. |
Description | The description of the instrument mode as defined in the Configure Tune section. |