7.5
Section 7
TroubleshooTing
Pinnacle Operators Manual
Pickering Laboratories Inc.
COMMON CHROMATOGRAPHY PROBLEMS continued
OBSERVED PROBLEM COMMON CAUSE ACTION TO TAKE NOTES
Peaks disappear or diminish Improper Reagent preparation
Out of Reagent
Reactor at wrong temperature
Reagent flow rate improper
Dirty flowcell
Dirty autosampler
Deteriorated samples
Metal contamination of column due to
poor sample preparation or corrosion
in system
Oxidized TRIONE or OPA
Reagent pump mis-adjusted
Iron contamination of column.
Prepare fresh reagents
Prepare fresh standards from neat
reference material.
Test with a second fluorescent or UV/
VIS detector.
Change the rotor seal of the
autosampler or use a manual
injector.
Flush amino acid column with
regenerant.
Check reactor temperature
Clean the flowcell
Follow the procedure for Iron removal
from the column on Page 7.9
Remove all stainless steel frits from
reservoirs
Clean or replace any corroded parts.
Flush Glyphosate column with Restore
All disappear except 1-naphthol and
carbaryL = OPA reagent expired
All disappear except 1-naphthol = Out
of Hydrolysis Reagent
Varied peak size, some missing =
Reactor at wrong temperature
All peaks diminish = dirty flowcell,
autosampler, or deteriorated samples
Solution standards, even stored in
ampoules, are not reliable (esp.
when dissolved in ACN)
A UV-Vis detector set at 330nm may
be used
Iron contamination caused from
samples, long column storage,
stainless steel frits in the eluant
reservoirs, corrosion in system
Retention times not stable, especially
in early part of chromatogram
Re-equilibration time is too short.
Too much internal volume in HPLC
pump or pulse dampener.
Leaking proportioning valve in HPLC
Autosampler Problems
Increase it by two minute increments.
Re-plumb system as described in the
installation section for amino acids.
Artifacts in Baseline Contamination in Eluant reservoir
Corrosion of spargers or filters
Volatile amines used in laboratory
Replace eluants
Clean reservoir with soap and water
Remove spargers or eluant filters
Remove any reagents used in amine
synthesis, or cigarette smoke laden
clothing
Retention times drift over a long time Buildup of contaminants
Room temperature changes greatly
with the seasons
Flush the column
Air condition the room
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