Hitachi CHROMASTER 5160, Instruction Manual

Page: 341 / 1022

3.7.2
3.7.2 Degassing of Mobile Phase
There are various degassing methods. Use a method suitable
for your analytical purpose.
(1) Example of Degassing by Ultrasonic Wave (when mobile
phase is an organic solvent)
Example : Methanol 100%, mixed solution of
methanol 80% + acetonitrile 20%
Necessary device : Ultrasonic washer
(Be sure to fill the bath with water.)
Mobile phase
container
Be sure to
remove the cap.
Ultrasonic washer
(a) In an ultrasonic washer, place a mobile phase
container after adequate stirring (see “*” below).
* For using a mixed mobile phase, complete mixing
by means of a stirrer is required. Otherwise, poor
reproducibility or baseline drift will be caused.
NOTE : The mobile phase of an organic solvent must
always be degassed with an ultrasonic washer
containing water.
(b) Turn ON the power switch of the ultrasonic washer.
(c) As degassing progresses, small bubbles are
discharged and they gradually become larger.
Continue degassing until bubbles are no longer
discharged. This process takes about 5 to 10 minutes.
3 - 59