ADC 2
Instruction Manual, November 2016
Page 39
6.
Additional measurement values
Several approaches have been made to quantitatively measure the
effective humidity on a HPTLC plate. It has been proven that by
means of this principle for humidity control, the activity of the
plate can be controlled reproducibly. The figure below shows 4
different measurements and related transfer times from dry to
humid and vice versa. The HPTLC plates have been weighted with
a precision balance.
Fig.18: Measurement of the humidity of the HPTLC plate by weighting. It has been
shown, that within 2 – 5 minutes a stable equilibrium is reached – for the humidifying as
well as the drying process (75% rH:10 minutes). Used plate material: Merck HPTLC
plates silica gel 60 F 254.
Fig. 19 shows the values for water absorption for different silica
gels from Merck (courtesy Merck). Humidity larger than 70% is
producing irreversible reactions in the binder and should be
avoided.
Fig.19: Humidity adsorption of different silica gel.
Adsorption Isotherms for Silicagel H2O (20deg C)
0
10
20
30
40
50
60
70
80
90
100
0
10
20
30
40
50
60
70
80
90
100
Relative Humidity
A
ds
or
pt
ion
[W
e
ight
%
,
nor
m
.
K
G
Ty
p
1
0
0
]
Typ 100
Typ 60
Typ 40
CAMAG (Switzerland)
· Sonnenmattstrasse 11 · CH-4132 Muttenz 1
Telephone
+
41 61 467 34 34 · Fax
+
CAMAG (Germany)
· Bismarckstraße 27-29 · D-12169 Berlin
Telephone
+
49 30 516 55 50 · Fax
+
49 30 795 70 73 · E-Mail:
CAMAG Scientific Inc. (USA)
· 515 Cornelius Harnett Drive · Wilmington, NC 28401
Telephone 800 334 3909 · Fax 910 343 1834 · E-Mail:
www.camag.com
Summary of Contents for ADC 2
Page 1: ...INSTRUCTION MANUAL ADC 2 ...
Page 41: ......
