Waters ACQUITY UPLC M-Class System Manual page 65

Suspected cause
Loose fittings or crimped lines before or after
the column
Inadequate solvent blending
NanoFlow sprayer/emitter problem
Increased background caused by possible:
• Dirty source
• Detector setting too high
• Electronic noise
• Column problem
• Solvent clusters
Dirty flow cell Ultraviolet (UV), system only
Possible solution
Inspect all fittings and tubing. Replace as
necessary.
If the baseline is steady when running a
premixed solvent, then:
Clean or replace the emitter.
See also:
Installation and Maintenance Guide on the
documentation CD.
Ensure cleanliness of solvents and proper use
of the column:
Clean the flow cell.
November 26, 2019, 715003588 Revision C
Page 65
• Ensure that A and B pumps are delivering
solvent correctly.
• For shallow gradients or protein
applications running at lower pressure,
switch to the mixer kit for the 1-mm column.
Universal NanoFlow Sprayer
• Adjust the detector setting and refer to the
appropriate documentation for that
instrument.
• Clean the source and sonicate the sample
cone in 50:50 methanol:water.
• Optimize the source conditions.