Sparging The Mobile Phase And Flushing The Solvent Lines - LC Packings SWITCHOS II User Manual

Installation and Getting Started

2.6.3 Sparging the Mobile Phase and Flushing the Solvent Lines

Although the Switchos loading pump is controlled via the CHROMELEON
software, initial system preparation is done with the pump on an off-line basis
(i.e. the pump is operated locally).
To prepare the system for a separation:
a) Power up the Switchos and make certain that power is provided to the
pump.
b) Check that the pump head backflushing system is operating. A solution of
isopropanol/water (1:1) is commonly used but other solvents can be used (if
any of the buffer components are not soluble in this mixture, reduce the
fraction of propanol). If desired you can reduce evaporation of the
backflushing solution by connecting the two backflush ports. A 5 mL syringe
is provided to backflush the head and fill the reservoir.
Note: The pump head of the pump should be backflushed with propanol/water
(1:1). If crystalline materials are deposited in the pump head, irreversible damage
to seals and or the piston may result; this will dramatically shorten the life of
these components.
c) Inspect all fittings. If there is a salt deposit by a joint, it is probable that a
leak has occurred and the fitting should be cleaned and tightened. When you
tighten a fitting, do not overtighten. Check that the solvent filters are clean,
if not they are not clean, they should replaced.
d) Fill the solvent reservoirs with the mobile phases to be used for the
application.
Caution: Only use the shielded solvent reservoirs supplied with the Switchos.
CAUTION
Caution: Do not operate the He lines a higher pressure than 4 bar (60 PSI).
CAUTION
Close the He-shut off valves when the system is in idle state or not used.
Note: All four solvent bottles must be filled and purged (even if the application
requires less than four mobile phases) to assure proper function of the system.
Fill solvent bottles that will not be used with methanol/water (1/1).
Note: The solvents must be degassed via the He degassing technique described
below. If other techniques are used (e.g. vacuum degassing) the performance of
the system will be seriously degraded and the performance specifications will not
be obtained.
e) Open the He Shut-off valves by rotating the knob so that the line on the
valve is vertical (FIGURE 2-9) and open the He Regulating Valve for maximum
sparging (FIGURE 2-10A). Allow sparging to continue for approximately 10
minutes at a rapid rate, then lower the He flow rate to maintenance mode
(FIGURE 2-10B).
2-10
D850R3
User's Manual Switchos