Waters XTerra and XTerra Prep Columns - Manual (Page 3)

[ Care and Use ManUal ]
XTerra Columns 3
d. SLIPFREE Connectors
A SLIPFREE Connector guarantees a void-free connection because
it pushes the tubing into the endfitting. This design comes
installed on the tubing. 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.
Minimization of band spreading
The following figure 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 5: Effect of Connecting Tubing on System
f. Measuring System Bandspread Volume
1. Disconnect column from system and replace with a zero dead
volume union
2. Flow rate 1 mL/min. This should be performed on a single
wavelength detector (not a PDA/DAD)
3. Dilute a test mix in mobile phase to give a detector sensitiv-
ity 0.5-1.0 AUFS (can use the system start up test mix
which contains uracil, ethyl and propyl parabens; Waters
P/N 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:
Bandspread (µL) = PW (seconds)/60 (see Figure 6)
Typical LC system should be 100 µL ± 30 µL
Microbore (2.1mm i.d. and smaller) system should be no
greater than 20-40 µL
Figure 6: Determination of System Bandspread Volume using the
5-Sigma Method
g. Measuring Gradient Delay Volume
1. Replace the column with a zero dead volume union.
2. Determine the gradient-delay or dwell volume for your system
by performing the following test. Prepare eluent A (pure solvent,
such as methanol) and eluent B (solvent plus sample, such as
5.6 mg/mL propylparaben in methanol).
3. Equilibrate the system with eluent A until a stable baseline is
achieved. Switch to 100% eluent B and record the half height of
the step. Refer to Figure 7 for an illustration. The dwell volume
should be less than 1 mL. If this is not the case, see section on
System Modifications to reduce your system volume.
System Volume
4.4 %h
5
Waters Part Numbers for SLIPFREE Pre-assembled Tubing
Tubing Length 0.005” i.d. 0.010” i.d. 0.020” i.d.
Single SLIPFREE ® 6 cm PSL 618000 PSL 618006 PSL 618012
Single SLIPFREE ® 10 cm PSL 618002 PSL 618008 PSL 618014
Single SLIPFREE ® 20 cm PSL 618004 PSL 618010 PSL 618016
Double SLIPFREE ® 6 cm PSL 618001 PSL 618007 PSL 618013
Double SLIPFREE ® 10 cm PSL 618003 PSL 618009 PSL 618015
Double SLIPFREE ® 20 cm PSL 618005 PSL 618011 PSL 618017
Figure 4: Single and Double SLIPFREE Connectors
Diluted/Distorted Sample Band
0.005 inches
0.020 inches
0.040 inches