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2 Mode of operation of ultrafiltration
IC equipment: Inline Ultrafiltration 2 - push mode
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3
2 Mode of operation of ultrafiltration
One peristaltic pump delivers a continuous flow of sample solution at a
high rate through the sample chamber of the ultrafiltration cell. The sam-
ple flows along the filtration membrane to the sample outlet and into the
waste container.
At the same time, a second peristaltic pump generates a vacuum in the
filtrate chamber of the ultrafiltration cell, thus aspirating the sample solu-
tion through the filtration membrane. The filtrate reaches the sample loop
and is then injected.
20 to 25% of the original sample solution volume is analyzed as filtrate.
The remainder flows into the waste container.
There are 2 options to connect the ultrafiltration cell. The push mode
2.1
Mode of operation of the push mode
The basic principle of the push mode is that the sample is delivered by
pushing it.
In push mode, one peristaltic pump is installed between the sample
changer and the sample inlet of the ultrafiltration cell. The other peristaltic
pump is installed between the filtrate outlet and the injector. The sample
flows through both peristaltic pump tubings before analysis. As the peri-
staltic pump tubings have a high volume, the required sample volume is
higher in the push mode than in the pull mode
.
2.2
Mode of operation of the pull mode
The basic principle of the pull mode is that the sample is delivered by pull-
ing it.
In pull mode, one peristaltic pump is installed between the sample outlet
of the ultrafiltration cell and the waste container. The other peristaltic
pump is installed between the injector and the waste container. Rinsing
the additional volume of the peristaltic pump tubings is not necessary.
Thus, the required sample volume is lower in the pull mode than in the
push mode
.
