IonPac CS14 Manual
Doc. No. 034848-10
Page 34 of 54
5.15 The Isocratic Separation of Ethanolamine and the Group I & II Cations
The IonPac CS14 can be used to monitor the amine content in the quality control of chemical additives, process solutions,
plating baths, and scrubber solutions.
Ethanolamine and ammonium are very difficult to resolve isocratically using methanesulfonic acid or methanesulfonic acid
modified with acetonitrile. To optimize resolution, the 18-Crown-6 ether complexing agent can be added to the eluent. 18-
Crown-6 forms a strong complex with monovalent cations such as potassium, ammonium and ethanolamine. This eluent can
be used in the AutoSuppression Recycle Mode.
When converting the column back to eluents without 18-Crown-6 ether, the column is washed with an acetonitrile/deionized
water gradient from 5% to 40% acetonitrile, held for 20 minutes and then reversed back to the new operating conditions.
Sample Loop Volume:
4.5 µL (2-mm), 18 µL (4-mm)
Analytical Column:
IonPac CS14 Analytical Column
Eluent:
10 mM Trifluoroacetic acid/8 mM 18-Crown-6/1.2% Acetonitrile
Eluent Flow Rate:
0.25 mL/min (2-mm), 1.0 mL/min (4-mm)
SRS Suppressor:
Cation Self-Regenerating Suppressor, CSRS ULTRA (2-mm or 4-mm)
External Water Mode
or MMS Suppressor:
Cation MicroMembrane Suppressor, CMMS III (2-mm or 4-mm)
MMS Regenerant:
100 mN TBAOH
(tetrabutylammonium hydroxide)
Expected Background Conductivity:
< 3 µS
Storage Solution:
Eluent
Figure 14
The Isocratic Separation of Ethanolamine
and the Group I & II Cations
Analyte
mg/L
1.
Li
+
1.0
2.
Na
+
4.0
3.
Mg
2+
5.0
4.
Ca
2+
10.0
5.
Ethanolamine
5.0
6.
NH
4
+
5.0
7.
K
+
10.0
1 mg/L = 1 ppm
0
30
6 0
μ
S
0
M inu te s
1
2
3
10
5
4
5
6
7
15
45
