Waters ACQUITY UPLC M-Class System Manual page 68

Suspected cause
Inlet lines blocked
Mobile phase contaminated
Fluid leak
4.3.2.4 Broad peaks
Suspected cause
Detector time constant or filter is too high (non-
MS detectors).
MS detector scan rate is too low.
User observes too much peak smoothing.
4.3.2.5 Early eluting peak issues
Suspected cause
Injection volume or sample concentration is too
high.
Sample diluent too high in organic for the initial
mobile phase.
Needle weak wash solvent is too high in
organic.
The method or part of the method is isocratic.
User observes incorrect trapping or column
conditions.
Possible solution
See also:
Performance LC/MS and HPLC/MS Systems
on the documentation CD.
Refer to the applicable solvent manager
overview and maintenance guide on the
documentation CD.
Possible solution
Ensure that time constant is as low as possible
while still minimizing baseline noise.
Increase the scan rate to obtain more data
points across the peak.
Reduce smoothing to prevent peak shape
distortion.
Possible solution
Reduce the injection volume or reduce the
percentage of organic in the diluent.
Ensure that the needle wash solution is similar
to the initial mobile phase.
Use a gradient method in which all peaks are
typically the same width.
Review the trapping parameters and reset to
improve conditions.
November 26, 2019, 715003588 Revision C
Page 68
• Inspect lines for blockages and replace
tubing if necessary.
• Clean the solvent inlet filter frit and replace
the frit if necessary.
Controlling Contamination in Ultra
• Reduce the injection volume.
• Dilute the sample.