Waters XBridge Columns - Manual (Page 6)

[ Care and Use ManUal ]
XBridge ™ Columns 6
Note: If a column has been run with a mobile phase that contains for mate
(e.g., ammonium formate, formic acid, etc.) and is then flushed with 100%
acetonitrile, slightly longer equilibration times may be nec essary when the
column is re-installed and run again with a formate-containing mobile phase.
slightly longer equilibration times may be necessary when the column is
re-installed and run again with a formate-containing mobile phase.
VI. ConneCtInG the Column to the hplC
a. Column Connectors and System Tubing Considerations
Tools needed:
• 3/8 inch wrench
• 5/16 inch wrench
Handle the column with care. Do not drop or hit the column on a hard
surface as it may disturb the bed and affect its performance.
1. Correct connection of 1/16 inch outer diameter stainless steel tubing lead-
ing to and from the column is essential for high-quality chromatographic
results.
2. When using standard stainless steel compression screw fittings, it is
important to ensure proper fit of the 1/16 inch outer diameter stainless steel
tubing. When tightening or loosening the compression screw, place a 5/16
inch wrench on the compression screw and a 3/8 inch wrench on the hex
head of the column endfitting.
Note: If one of the wrenches is placed on the column tube flat during this
process, the endfitting will be loosened and leak.
3. If a leak occurs between the stainless steel compression screw fitting
and the column endfitting, a new compression screw fitting, tubing and fer-
rule must be assembled.
4. An arrow on the column identification label indicates correct direction
of solvent flow.
Correct connection of 1/16 inch outer diameter stainless steel tubing leading
to and from the column is essential for high-quality chromatographic results. To
obtain a void-free connection, the tubing must touch the bottom of the column
endfitting. It is important to realize that extra column peak broadening due to
voids can destroy an otherwise successful separation. The choice of appropriate
column connectors and system tubing is discussed in detail below.
t
Figure 1: Waters and Parker Ferrule Types
Due to the absence of an industry standard, various column manufactur-
ers have employed different types of chromatographic column connectors.
The chromatographic separation can be negatively affected if the style
of the column endfittings does not match the existing tubing ferrule
settings. This section explains the differences between Waters style
and Parker style ferrules and endfittings (Figure 1). Each endfitting style
varies in the required length of the tubing protruding from the ferrule. The
XBridge
™ column is equipped with Waters style endfittings that require a
0.130 inch ferrule depth. If a non-Waters style column is presently being
used, it is critical that ferrule depth be reset for optimal performance
prior to installing an XBridge
™ column.
In a proper tubing/column connection (Figure 2), the tubing touches the bottom
of the column endfitting, with no void between them.
Figure 2: Proper Tubing/Column Connection
The presence of a void in the flow stream
reduces column performance. This can
occur if a Parker ferrule is connected to
a Waters style endfitting (Figure 3).
Note: A void appears if tubing with a Parker ferrule is connected to a Waters
style column.
Figure 3: Parker Ferrule in a Waters Style Endfitting
There is only one way to fix this prob-
lem: Cut the end of the tubing with
the ferrule, place a new ferrule on the
tubing and make a new connection.
Before tightening the screw, make
sure that the tubing bottoms out in the
endfitting of the column.
Conversely, if tubing with a Waters ferrule is connected to a column with
Parker style endfitting, the end of the tubing will bottom out before the
ferrule reaches its proper sealing position. This will leave a gap and create
a leak (Figure 4).
Note: The connection leaks if a Waters ferrule is connected to a column with
a Parker style endfitting.
Void
Waters Ferrule Setting Parker Ferrule Setting
0.090 inches
.130” .090”