Performance Optimization; Best Practices To Improve Performance; Autozeroing The Flow Transducers; Flow Ramping - Waters ACQUITY UPLC M-Class System Manual

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Performance optimization

Optimal performance of an ACQUITY UPLC M-Class system is achieved when users have a
good understanding of the effects of dispersion and carryover, leak-prevention, and sample-
preparation techniques.

2.1 Best practices to improve performance

Review Waters recommendations for achieving more reproducible chromatography.

2.1.1 Autozeroing the flow transducers

Autozero the flow transducers under the following conditions:
• Changes in lab temperature observed from when the transducers were last autozeroed.
• Seasonally, when the exterior temperature significantly changes.
• When a significant change is made to the mobile phase composition being used (for example,
changing from a mobile phase containing formic acid to one containing ammonium formate or
from acetonitrile to methanol).
Note:
When refreshing mobile phase, an autozero is not required.

2.1.2 Flow ramping

Requirement:
configuration, you must utilize flow ramping. Otherwise, when valves are switched, the sudden
pressure change could cause back flow in the column or damage to the column bed. This can
impact the chromatographic reproducibility and performance. In addition, a rapid pressure change
on the column can fracture the fitting. This allows particles to enter and block the emitter or valves
causing the system to overpressure.
To turn on flow ramping:
1. From the Inlet Method Parameters page, click Advanced.
2. Select Flow rate is ramped to zero, valve position changes, flow rate is ramped from
the Specify flow rate behavior when a valve changes position field.
When using 75-µm columns in a direct injection configuration or in any trapping
November 26, 2019, 715003588 Revision C
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