 Seawater
samples, brine samples, strongly sweetened refreshment
drinks: whenever you encounter concentrated samples
there is the risk of the separating column becoming
overloaded and adversely affecting the quality
of the analysis. Previously such solutions had
to be diluted, either manually, inline or with
a special dilution sample changer. Now there is
a new solution: the "internal loop"!
In ion chromatography 10, 20, 50 or 100 µL
of the sample is injected as standard; in contrast,
the internal loop only injects either 1.0 or 0.25
µL. For example, if the 0.25 µL loop
is used then the injected volume is smaller than
that injected with the standard 20 µL loop
by the factor 100. This means that samples in
the g/L concentration range can be injected undiluted.
The internal loop or the so-called rotor can
be ordered individually with sample volumes of
0.25 or 1.0 µL. In order to be able to use
it the rotor built into the standard 6-way injection
valve is simple exchanged, The 6-way stator remains
unchanged. As only four openings of the 6-way
stator are required for working with the internal
loop, this means that two of its openings must
be sealed. This is why a version
with a special 4-way stator is also available.
In this case the rotor (0.25 µL) and stator
(4-way) of the standard valve must be exchanged.
The valve drive always remains unchanged.
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