Waters ACQUITY UPC2 Trefoil Columns - Manual (Page 5)

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[ CARE AND USE MANUAL ]
ACQUITY UPC 2 Trefoil Columns Care & Use
appropriate additive. Additives tend to improve peak shape and
control the retention characteristics of analytes, but can also
impart different selectivities. It is recommended to flush and
remove additives and salts from the column before placing the
column into storage.
d. Pressure
ACQUITY UPC 2 Column hardware and packing materials are
packed and tested to pressures of up to 6,000 psi (414 bar or
41 Mpa).
e. Band Spreading Minimization
The ACQUITY UPC 2 System has been designed to minimize band
spreading. Deviation from Waters specified tubing could result
in deterioration of chromatographic performance due to band
spreading induced by inappropriate tubing i.d. Figure 1 shows the
influence of tubing internal diameter on system band spreading
and peak shape. As can be seen, the larger tubing diameter causes
excessive peak broadening and lower sensitivity.
Figure 1: Effect of connecting tubing on system.
IV. T ROUBLESHOOTING
1. One of the most common problems with regards to columns
is incorrect or insufficient priming of the co-solvent/modifier
pump. If no peaks are observed after an injection or unusually
long retention times are observed, check the priming of the
co-solvent/modifier pump first.
2. If you see frosting on the column at the inlet or outlet, tighten
the compression screw on that side. If tightening doesn’t work,
depressurize the system and the column, and then replace the
fitting that is not sealing correctly.
3. If you continue to see frosting on the column, turn off the CO
2
and vent the system. Allow the column to depressurize fully
before disconnecting the inlet or outlet. Please contact your
Waters representative for additional support.
V. COLUMN CLEANING, ADDITIV ES AND STORAGE
Changes in peak shape, peak splitting, shoulders on the
peak, shifts in retention, change in resolution or increasing
backpressure may indicate contamination of the column.
Flushing with high concentrations of organic solvent, taking
care not to precipitate buffers, is usually sufficient to remove
the contaminant. If the flushing procedure does not solve the
problem, purge the column using the following cleaning and
regeneration procedures.
a. Cleaning
Use the cleaning routine that matches the properties of the
samples and/or what you believe is contaminating the column
(see Table 4). Placing the column on an ACQUITY UPLC System
(or HPLC system) will enable the use of a wide range of solvents
to improve cleaning.1 Flush columns with 10 column volumes
of solvent. Increasing column temperature increases cleaning
efficiency. If the column performance is poor after cleaning and
regenerating, call your local Waters office for additional support.
Polar Samples Non-Polar Samples
1. Methanol 1. Isopropanol
2. Isopropanol 2. Heptane
3. Methanol 3. Isopropanol
4. Mobile Phase 4. Mobile Phase
Table 2: Column Cleaning Sequence.
Diluted/Distorted Sample Band
0.005 inches
0.020 inches
0.040 inches