CAMAG ADC 2, Инструкция по эксплуатации

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ADC 2
Instruction Manual, November 2016 Page 33
Appendix A Option Humidity Control (022.8360)
The chromatographic separation on silica gel can be influenced by
the activity of the stationary phase and is thus depending on the
relative humidity (rH) in the laboratory. The rH is varying signifi-
cantly for different climatic regions or different seasons which re-
sults in varying chromatographic results.
With the option “Humidity Control” the activity of the stationary
phase is adjusted with air of a defined relative humidity. This facili-
tates the possibility to standardize all developments either to a
fixed relative humidity or to select a specific humidity for a specific
task.
With the ADC 2 and the option “Humidity Control” favorable
chromatogram comparisons can be ensured at all times and all
places. As a result, chromatography performed in humid summers
or coastal climates can be compared to those performed in dry
winters or in highland climates.
1. General / saturated salt solution
The desired humidity is adjusted in the ADC2 by means of a satu-
rated salt solution (not included in shipment). Alternatively it is
possible to achieve very dry atmospheric conditions if a molecular
sieve (not included in shipment) is used instead.
For nearly every relative humidity a corresponding salt solution can
be found, which produces the desired climatic condition (relative
humidity). Good experimental results have been achieved with
salts generating moderate humidity (40 – 50%) and with a mo-
lecular sieve generating high plate activities (below 20%). Relative
humidity above 70% is not recommended because of problems
with the binder.
Extreme humidity or humidity which differs a lot from the ambient
air of the lab takes longer to equilibrate in the ADC2.
As a guideline for possible salt solutions the following table can
be used as a start off.