Thermo Scientific ETD, Руководство по началу работы

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5
Performing an ETD Infusion Experiment
Troubleshooting an AGC Target Error
Thermo Scientific MS/ETD System Getting Started Guide 35
Troubleshooting an AGC Target Error
If the AGC target is not reached because of the maximum injection time limit, the system
displays an error message:
Maximum Injection time limit exceeded.
This implies that the sensitivity of the reagent ion source is too low. There are several ways to
deal with this error:
• Increase the sensitivity of the source by running the automatic tuning of the reagent ion
source; see “Tuning the Reagent Ion Optics” on page 14 .
• Clean or change the ion volume; refer to Chapter 6, “Maintenance,” in the ETD Module
Hardware Manual . The sensitivity decrease might be due to a dirty ion volume. A
sufficiently contaminated ion volume causes the maximum injection time limit to be
exceeded.
• Clean the reagent ion source and its optics; refer to Chapter 6, “Maintenance,” in the
ETD Module Hardware Manual . The sensitivity decrease might be due to a dirty reagent
ion source, its optics, or both. A contaminated reagent ion source or its optics can also
cause the maximum injection time limit to be exceeded.
• Increase the emission current in the Reagent Ion Source dialog box ( Figure 8 on page 16 ).
However, an increase in emission current might decrease the filament life.
• Increase the maximum injection time limit. This is a temporary way to eliminate the error
message. You can increase the maximum injection time limit up to the limits imposed by
the overall scan cycle time.
The maximum injection time limit and AGC target influence the ETD reaction results.
Obtaining an ETD Spectrum for Angiotensin I
This section assumes that you are infusing Angiotensin I into the LTQ XL/ETD or
LTQ Velos/ETD system according to the procedures in the
LTQ Series Getting Started Guide .
For instructions about preparing the Angiotensin I solutions, see Appendix B, “Angiotensin I
Solutions.”
 To obtain an ETD spectrum of Angiotensin I
1. Open the Tune Plus window; see the instructions on page 13 .
2. Click the On/Off/Standby button to select the On mode.
3. Turn on the reagent ion source; see “Turning On the Reagent Ion Source” on page 28 .
On Off Standby