Waters High Strength Silica Columns - Manual (Page 2)

[ Care and Use ManUal ]
HSS HPLC Columns 2
II. CONNECTING THE COLUMN TO THE HPLC SYSTEM
a. Column Connection
Handle the column with care. Do not drop or hit the column on a hard
surface as this 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. An arrow on the column identification label indicates correct
direction of solvent flow.
3. 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.
Caution: If one of the wrenches is placed on the column flat
during this process, the endfitting will be loosened and leak.
Under-tightening compression screws or using worn ferrules can
lead to solvent leaking. Care should be taken to check all column
connections for leaks to avoid exposure to solvents and the
hazards associated with such exposure including risks to health
and electrical
connections.
4. If a leak occurs between the stainless steel compression screw fit-
ting and the column endfitting, a new compression screw fitting,
tubing and ferrule must be assembled.
It is important to realize that extra column peak broadening can
destroy a successful separation. The choice of appropriate column con-
nectors and system tubing is discussed in detail below.
b. Column Connectors and System Tubing Considerations
Due to the absence of an industry standard, various column man
facturers have employed different types of chromatographic column
connectors. The chromatographic performance of the separation can
be negatively affected if the style of the column endfittings does not
match the existing tubing ferrule setting. This section explains the
differences between Waters style and Parker style ferrules and endfit-
tings (Figure 1). Each endfitting style varies in the required length
of the tubing protruding from the ferrule. The HSS HPLC column is
equipped with Waters style endfittings, which require a 0.130 inch
ferrule. If a non-Waters style column is presently being used, it is
critical that ferrule depth be reset for optimal performance prior to
installing a HSS HPLC column. In a proper tubing/column connection
(Figure 2), the tubing touches the bottom of the column endfitting,
with no void between them.
Attention: A void will occur if tubing with a Parker ferrule is con-
nected to a Waters style endfitting (Figure 3). This will dramatically
reduce the efficiency of the column and cause peak shape distortion.
Figure 1: Waters and Parker Ferrule Types
Figure 2: Proper Tubing/Column Connection
Tubing touches the bottom of the column endfitting, with no void
between them.
Attention: A void will occur if tubing with a Parker ferrule is con-
nected to a Waters style endfitting (Figure 3). This will dramatically
reduce the efficiency of the column and cause peak shape distortion.
Figure 3: Parker Ferrule in a Waters Style Endfitting
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 tighten-
ing 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).
Caution: The connection will leak if a Waters ferrule is connected to a
column with a Parker style endfitting.
Waters Ferrule Setting Parker Ferrule Setting