Waters ACQUITY UPLC CSH Columns - Manual (Page 8)

[ Care and Use ManUal ]
ACQUITY UPLC CSH Columns 8
V. addItIonaL InForMatIon
a. Tips for maximizing ACQUITY UPLC CSH Column
Lifetimes
1. To maximize ACQUITY UPLC CSH 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 backpressure 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?