Waters Ultrahydrogel Columns - Manual (Page 3)

[ Care and Use ManUal ]
Ultrahydrogel Columns 3
f. Solvent and Sample Preparation
• Use LC grade solvents, filtered through a GHP (or other
suitable) membrane to remove micropar¬ticulate matter above
0.45 µm. Use of the Waters Solvent Clarification Kit, (P/N
WAT085113) is recommended.
• Particulate-free solvents reduce the problem of plugged filters
and column beds and preserve column life.
• Vacuum filtration or sonication of solvents may be used to
remove dissolved gases which could affect the solvent delivery
system.
• Always filter prepared sample solutions to prevent excessive
pressure buildup due to particulate matter (Acrodisc
® Filters are
available for this purpose).
• Use of a Waters In-Line Precolumn Filter (P/N WAT084560) is
recommended to obtain maximum column
g. Guard Columns
While guard columns are not generally used for organic GPC, they
will remove and/or filter many impurities found in aqueous soluable
samples such as saccharides, peptides and hydrolyzates that might
adsorb ir¬reversibly on the Ultrahydrogel column. Guard columns
are also used to remove particulates and strongly retained sample
components which, ultimately decrease column life from the sample
and solvent. Guard columns will aid in obtaining consistently
reliable and reproducible results with your Ultrahydrogel column.
Ultrahydrogel Guard Columns are available in both Ultrahydrogel
(P/N WAT011565) and Ultrahydrogel DP (P/N WAT011570)
configurations.
Guard columns have a finite capacity for impurities. Either the
number of sample injections or an observed change in backpressure
will indicate when a change of guard column is required. If the
capacity of the guard column is exceeded, undesirable contaminants
will elute onto the analytical column.
While guard columns will help lengthen column life, they perform a
specific function for a short period of time and must be changed or
regenerated often. It is important to use good laboratory practices
to increase column life. Ultrahydrogel Guard Columns can be
regenerated by flushing with 6 - 10 column volumes of one or more
of the following solvents:
•
Salt buffer (0.5M-1.OM)
• High pH buffer (pH 9-12)
• Urea, SDS or other surfactants
• Low pH buffer (pH 2-3)
• Methanol or acetonitrile
h. Column Installation
Remove the end cap fittings from your steel column and save
them to recap the column when it is removed from the system. The
column outlet is indicated by an arrow on the label showing the
direction that the sol¬vent should flow.If solvent is not visible when
the end cap is removed, connect the outlet side of the column to the
system and slowly pump solvent through the column to expel the air.
Rapid pressurization or solvent flow may cause degradation of the
column. When solvent flow is visible at the inlet side of the column,
connect the column in the direction of normal flow and attach the
inlet side of the column to the injector or guard column. Follow the
next four steps of this procedure to cut tubing to connect a new steel
column, or to improve the end connections on your existing fittings.
NOTE: WHEN CHANGING COLUMNS A NEW FERRULE MUST BE
CAREFULLY RESEATED TO INSURE THAT NO DEAD VOLUME IS
PRESENT.
1. Using a three-cornered file with a cutting edge scribe the
circumference of the tubing at the desired break.
2. Grasp the tubing on both sides of the scribe mark with cloth-
covered pliers (to prevent marring the tube surface) and gently
work the tube back and forth until it separates.
3. Slide the compression fitting, followed by the ferrule (large end
of the taper first) over the tube. Be certain to bottom the tube in
the fitting seat to assure a leak-free connection.