IonPac CS14 Manual
Doc. No. 034848-10
Page 28 of 54
5.11 Gradient Elution of Cyclohexylamine
Power water samples are often treated with cyclohexylamine as a corrosion inhibitor. The determination of cyclohexylamine in
the presence of ammonia, Group I & II cations can be accomplished by gradient elution using 9 mM methanesulfonic acid
(MSA) with 5% acetonitrile (ACN) as the initial eluent and then stepping to 20 mM methanesulfonic acid (MSA) with 8%
acetonitrile. The CSRS is used in the AutoSuppression External Water Mode.
Sample Loop Volume:
6.25 µL (2-mm), 25 µL (4-mm)
Analytical Column:
IonPac CS14 Analytical Column
Eluent:
See Gradient Program listed below
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:
< 1 µS
Storage Solution:
Eluent
Eluent 1:
Type I DI Water
Eluent Flow Rate:
1.0 mL/min
Eluent 2:
100 mM MSA
(4-mm System)
Eluent 3:
50% Acetonitrile
TIME (min)
%E1
%E2
%E3
Comments
Equilibration
0.0
81
9
10
Equilibrate to 9.0 mM MSA / 5.0% ACN
7.0
81
9
10
Analysis
0.0
81
9
10
Inject, 9.0 mM MSA / 5.0% ACN
0.1
81
9
10
Inject Valve to Load Position
7.0
81
9
10
9.0 mM MSA / 5.0% ACN, step change to
7.1
64
20
16
20 mM MSA / 8.0% ACN
13.0
64
20
16
20 mM MSA / 8.0% ACN
13.1
81
9
10
9.0 mM MSA / 5.0% ACN
Figure 11
Analysis of Cyclohexylamine
Analyte
mg/L
1.
Li
+
1.0
2.
Na
+
4.0
3.
NH
4
+
5.0
4.
K
+
10.0
5.
Mg
2+
5.0
6.
Ca
2+
10.0
7.
Cyclohexylamine
50.0
1 mg/L = 1 ppm
0
10
20
μ
S
0
Minutes
1
2
3
10
5
4
5
6
7
