Waters XBridge Columns - Manual (Page 7)

[ Care and Use ManUal ]
XBridge ™ Columns 7
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 end in break-
ing 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 Keystone,
Inc. SLIPFREE
® connector to always 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
SLIPFREE ® Connector Features:
• Tubing pushed into endfitting, thereby guaranteeing a
void-free connection
• Connector(s) come(s) installed on tubing
• Various tubing IDs and lengths available
• Fingertight to 10,000 psi – never needs wrenches
• Readjusts to all column endfittings
• Compatible with all commercially available endfittings
• Unique design separates tube-holding function from
sealing function
Table 5: Waters Part Numbers for SLIPFREE® Connectors
SLIPFREE ® Type 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
Band Spreading Minimization
Figure 6 shows the influence of tubing internal diameter on system band
spreading and peak shape. As can be seen, the larger tubing diameter
causes excessive peak broadening and lower sensitivity.
Figure 6: Effect of Connecting Tubing on System
b. Measuring System Bandspreading Volume
and System Variance
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
of 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.
Gap
Diluted/Distorted Sample Band
0.005 inches
0.020 inches
0.040 inches