Waters ACQUITY UPLC CSH130 C18 1.7 μm and XP 2.5 μm Columns - Manual (Page 8)

[ CARE AND USE MANUAL ]
ACQUITY UPLC CSH130 C
18
Columns 8
VI. ADDITIONAL INFORMATIONA.
Tips for maximizing ACQUITY UPLC CSH130 C
18
Column Lifetimes
1. To maximize ACQUITY UPLC CSH130 C
18
column lifetime, pay close
attention to:
• Water quality (including water purification system)
• Solvent quality
• Mobile-phase preparation, storage and age
• Sample, buffer and mobile-phase solubilities
• Sample quality and preparation.
2. When problems arise, often only one improper practice must be changed.
3. Always remember to:
• Use in-line filter unit or, preferably, a VanGuard Pre-column.
• Discourage bacterial growth by minimizing the use of 100%
aqueous mobile phases where possible.
• Change aqueous mobile phase every 24-48 hours (if 100%
aqueous mobile phase use is required).
• Discard old 100% aqueous mobile phases every 24-48 hours
to discourage bacterial growth.
• Add 5%-10% organic modifier to mobile phase A and adjust
gradient profile.
• Filter aqueous portions of mobile phase through 0.2 µm filter.
• Maintain your water purification system so that it is in good
working order.
• Only use ultra pure water (18 megohm-cm) water and highest quality
solvents possible. HPLC grade water is not UPLC grade water.
• Consider sample preparation (e.g., solid-phase extraction, filtration, etc).
4. Avoid (where possible):
• 100% aqueous mobile phases (if possible).
• HPLC-grade bottled water.
• “Topping off” or adding “new” mobile phase to “old” mobile phase.
• Old aqueous mobile phases. Remember to rinse bottles thoroughly and
prepare fresh every 24-48 hours.
• Using phosphate salt buffer in combination with high ACN concentrations
(e.g., > 70%) due to precipitation.
5. Don’t: assume a “bad” column is the culprit when high back pressure or split
peaks are observed. Investigate cause of column failure:
• Backpressure
• Mobile phase(s), bacteria, precipitation and/or samples
• Peak splitting
• Sample quality
• Injection solvent strength.
6. Remember: UPLC flow rates are often much lower and, therefore,
mobile phases last much longer (only prepare what you need or store
excess refrigerated).
7. Mobile-phase related questions to ask:
• Am I using 100% aqueous mobile phases? Am I able to add
a small amount of organic modifier to my mobile-phase A?
• Do I filter my aqueous mobile phases through 0.2 µm filters?
• How old is my mobile phase? Do I label the bottle with preparation date?
• Do I “top off” or do I prepare fresh mobile phases every 24-48 hours?
• What is the quality of my water? Has the quality recently changed? How
is my water purification system working? When was it last serviced?
• Am I working with a pH 7 phosphate buffer (which is VERY susceptible
to bacterial growth)?
8. Sample-related questions to ask:
• If I inject neat standards prepared in mobile phase do I observe
these problems?
• If I prepare my standards in water and prepare them like samples
(e.g., SPE, filtration, etc.) do I still observe these problems?
• Has the quality of my samples changed over time?