Waters XSelect CSH HPLC Columns - Manual (Page 6)

[ CARE AND USE MANUAL ]
6 XSelect CSH HPLC Columns
VI. CONNECTING T HE COLUMN TO T HE 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 leading 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 ferrule 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.
Figure 1: Waters and Parker Ferrule Types
Due to the absence of an industry standard, various column
manufacturers 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 XSelect CSH
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 XSelect CSH 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 problem: 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 Water ferrule is connected to a column with a
Parker style endfitting.
Figure 4: Waters Ferrule in a Parker Style Endfitting
Waters Ferrule Setting Parker Ferrule Setting
0.090 inches
.130” .090”
Void
Gap