Waters XSelect HSS HPLC Columns - Manual (Page 3)

[ Care and Use ManUal ]
XSelect HSS HPLC Columns 3
Figure 4: Waters Ferrule in a Parker Style Endfitting
There are two ways to fix the problem:
1. Tighten the screw a bit more. The ferrule moves forward, and
reaches the sealing surface. Do not overtighten since this may
break the screw.
2. Cut the tubing, replace the ferrule and make a new connection.
Alternatively, replace the conventional compression screw fitting
with an all-in-one PEEK
™ fitting (Waters Part Number PSL613315)
that allows resetting of the ferrule depth. Another approach is to use a
SLIPFREE
® connector to ensure the correct fit. The fingertight SLIPFREE
connectors automatically adjust to fit all compression screw type
fittings without the use of tools (Figure 5).
Figure 5: Single and Double SLIPFREE Connectors
Table 1. Waters Part Numbers for SLIPFREE Connectors
SLIPFREE Type
and Tubing
Internal
Diameter
Tubing Length
0.005” 0.010” 0.020”
Single 6 cm PSL 618000 PSL 618006 PSL 618012
Single 10 cm PSL 618002 PSL 618008 PSL 618014
Single 20 cm PSL 618004 PSL 618010 PSL 618016
Double 6 cm PSL 618001 PSL 618007 PSL 618013
Double 10 cm PSL 618003 PSL 618009 PSL 618015
Double 20 cm PSL 618005 PSL 618001 PSL 618017
c. Band Spreading Minimization
Internal tubing diameter influences system band spreading and peak
shape. Larger tubing diameters cause excessive peak broadening and
lower sensitivity (Figure 6).
Figure 6: Effect of Connecting Tubing on System
Diluted/Distorted Sample Band
0.005 inches
0.020 inches
0.040 inches
d. Measuring System Band Spread Volume
This test should be performed on an HPLC system with a single wavelength
UV detector (not a Photodiode Array (PDA)).
1. Disconnect column from system and replace with a zero dead
volume union.
2. Set flow rate to 1 mL/min.
3. Dilute a test mix in mobile phase to give a detector sensitivity
0.5-1.0 AUFS (system start up test mix can be used which
contains uracil, ethyl and propyl parabens; Waters Part Number
WAT034544).
4. Inject 2 to 5 μL of this solution.
5. Using 5-Sigma Method measure the peak width at 4.4% of peak height:
Band Spreading (μL) = Peak Width (min) x Flow Rate (μL/min)
= 0.1 min x 1000 μL/min
= 100 μL
Figure 7: Determination of System Band Spread Volume Using
5-Sigma Method