Waters Atlantis T3, DC18 and HILIC Silica Columns - Manual (Page 9)

[ Care and Use ManUal ]
Atlantis Columns 9
XIII. coLuMn cLeAnInG, reGenerAtInG And storAGe
a. Cleaning and Regeneration
A sudden increase in pressure or shift in retention or resolution may
indicate contamination of the column.
Atlantis T3 and dC
18
– Flush with a neat organic solvent to remove
the non-polar contaminant(s). If this flushing procedure does not solve
the problem, purge the column with a sequence of progressively more
non-polar solvents. For example, switch from water to tetrahydrofuran
to methylene chloride. Return to the standard mobile phase conditions
by reversing the sequence.
Atlantis HILIC Silica – Flush with 50:50 acetonitrile:water to remove
the polar contaminant(s). If this flushing procedure does not solve the
problem, purge the column with 5:95 acetonitrile:water.
Guard columns require replacement at regular intervals as determined
by sample contamination. When system backpressure increases above
a set pressure limit, it is usually an indication that the guard column
should be replaced. A sudden appearance of split peaks is also indica-
tive of a need to replace the guard column.
b. Storage
Atlantis T3 and dC
18
– For periods longer than four days, store the column
in 100% acetonitrile. Do not store columns in buffered eluents. If the
mobile phase contained a buffer salt, flush the column with 10 column
volumes of HPLC grade water (see Table 2 for common column volumes)
and replace with 100% acetonitrile for storage. Failure to perform this
intermediate step could result in precipitation of the buffer salt in the
column when 100% acetonitrile is introduced.
Atlantis HILIC Silica – For periods longer than four days, store the column
in 95:5 acetonitrile:water. Do not store in buffered eluents. If the mobile
phase contained a buffer salt, flush the column with 10 column volumes of
95:5 acetonitrile:water (refer to Table 2 for a listing of standard column
volumes) prior to storage.
Completely seal column to avoid evaporation and drying out of the bed.
Note: If a column has been run with a formate-containing mobile phase
(e.g., ammonium formate, formic acid, etc.) and is flushed to remove the
buffer, slightly longer equilibration times may be required after the column
is re-installed and run again with a formate-containing mobile phase.
XIV. Troubleshooting
Changes in retention time, resolution, or backpressure are often due to
column contamination (refer to “Column Cleaning, Regenerating and
Storage”). Information on column troubleshooting problems may be
found in HPLC Columns Theory, Technology and Practice, U.D. Neue,
(Wiley-VCH, 1997) or the Waters HPLC Troubleshooting Guide (Litera-
ture Code 720000181EN).