Preparatory Operations; Cautions On Measurement (Handling) - Hitachi CHROMASTER 5160 Instruction Manual

3.5 Preparatory Operations

3.5.1 Cautions on Measurement (Handling)

Cautions on displacement of mobile phase/wash fluid
(1)
Before attempting to exchange the mobile phase/wash fluid
with a different kind of mobile phase/wash fluid, make sure
that the liquid currently used and the liquid to be used are
mutually soluble. If they are not mutually soluble, perform
complete displacement on the flow path by using another
kind of liquid soluble in both of them, and then proceed to
displacement with the liquid of interest.
For displacement from a salt-containing solution to an
organic solvent, displace the salt-containing solution with
distilled water thoroughly and then proceed to displacement
to the organic solvent. (For displacement from an organic
solvent to a salt-containing solution, displace the organic
solvent with distilled water thoroughly and then proceed to
displacement to the salt-containing solution as in the case
mentioned above.)
The internal capacity per flow path of the degassing unit
including its tubing connection is approx. 12 mL.
For complete displacement, it is therefore required to feed
approx. 30 mL of solvent per flow path. When performing
displacement using the pump, set a flow rate to 5 mL/min
or less to prevent formation of air bubbles.
(2) Periodically replace mobile phase and wash fluid being
used with a new one to prevent possible development of
fungi.
(3) Set the wash fluid bottle at a position higher than the
autosampler.
NOTE: If the wash fluid bottle is set at a position lower
than the autosampler, a negative pressure may
occur inside the tubing to cause the formation of
air bubbles in the syringe, resulting in
unsatisfactory performance of the instrument.
(4) Cautions on storage
When not using the autosampler for a long time, turn power
off, wash the flow path thoroughly with distilled water, and
then fill and seal the flow path with methanol. In particular,
after using a buffer solution or salt-containing solution as
the mobile phase, there may occur such a
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