Troubleshooting M-Class System Devices - Waters ACQUITY UPLC M-Class System Manual

• Consider the likely causes of the problem. For example, unresponsive modules can mean that
power or signal cables are disconnected or improperly connected. A fluid or vacuum leak can
indicate defective tubing or valve connections.
• Look for the less obvious causes of a problem:
• Confirm that the system back pressure is appropriate.
• Determine the flow rate using a graduated cylinder.
• Determine gradient accuracy.
• Perform a column efficiency test.
• Define problems in detail, for example:
• Complete failure of analysis.
• Peaks incorrectly identified.
• Quantitative problems (bad precision or accuracy).
• Run a standard exactly as it was run at installation:
• Use a fresh, tested column.
• Use bottled, tested eluents.
• Adhere to these guidelines when evaluating results of the standard runs:
• Retention time reproducibility must be comparable to the results obtained during
installation (the standard deviation maximum is less than 0.25 min for six injections).
• Retention times must match those specified for the method.
• Peak areas must be comparable to the results obtained during installation.

4.3.2 Troubleshooting M-Class system devices

The following sections describe the most common chromatography, method parameters, and
sample problems defined at a system level.
4.3.2.1 Baseline or background fluctuations
Suspected cause
Solvent contamination
Erratic solvent manager pressure
Possible solution
Use only fresh, clean solvents.
See also:
Performance LC/MS and HPLC/MS Systems
on the documentation CD.
Prime the µBSM and ASM. If the problem
persists, troubleshoot the solvent manager
pressure.
November 26, 2019, 715003588 Revision C
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Controlling Contamination in Ultra