Waters iKey - Manual (Page 9)

9
[ CARE AND USE MANUAL ]
iKey
b. Storage
For periods longer than four days, store the reversed-phase iKey in 100% acetonitrile. Do not store iKeys in buffered eluents. If the mobile
phase contained a buffer salt, flush the reversed-phase iKey with 10 iKey volumes of HPLC grade water followed by 10 iKey volumes of
acetonitrile. Failure to perform this intermediate step could result in precipitation of the buffer salt in the column when 100% acetonitrile
is introduced. Completely seal the iKey to avoid solvent evaporation and drying out of the chromatographic bed.
Note: If an iKey has been run with a formate-containing mobile phase (e.g., ammonium formate, formic acid, etc.) and is purged with 100%
acetonitrile, slightly longer equilibration times may be necessary when the iKey is re-installed and re-wetted with that same formate-
containing mobile phase.
VII. T ROUBLESHOOTING iK EY PERFORMANC E
The table below lists symptoms, causes, and solutions for troubleshooting the iKey.
Symptom Cause Solution
Excessive baseline noise The emitter tip has residue on it Rinse the emitter tip in isopropanol.
Poor LC quality such as
retention time shift, or peak
width variance
Fluid leak
Use the Fluidic Integrity Test within the Console
software in combination with the Diagnostic iKey
to find and identify leaking components.
The iKey does not fit into the
ionKey source’s docking port
The iKey is upside down
Remove and orient the iKey so that the four ports
are on the left side.
a. Tips for Maximizing iKey Lifetimes
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To maximize iKey lifetime, pay close attention to:
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Water quality (including water purification systems);
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Solvent quality;
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Mobile phase preparation, storage and age;
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Sample, buffer and mobile phase solubilities;
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Sample quality and preparation.
■ ■
When problems arise, systematically troubleshoot potential causes one variable at a time in a systematic fashion.
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Always remember to:
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Discourage bacterial growth by minimizing the use of 100% aqueous mobile phases where possible;
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Discard and re-prepare aqueous mobile phase every 24 to 48 hours (if 100% aqueous mobile phase is required);
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Routinely maintain your water purification system to ensure it is functioning properly;
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Only use ultra-pure water (18 MOhm-cm) and highest quality solvent possible;
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Consider improving sample preparation (e.g., solid-phase extraction, filtration, centrifugation, etc.) when possible.
■ ■
Avoid when possible:
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100% aqueous mobile phases;
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HPLC-grade bottled water;
■ ■
“Topping off” your mobile phases.