IonPac CS14 Manual
Doc. No. 034848-10
Page 25 of 54
5.9
Isocratic Elution of Mono-, Di- and Trimethylamines and Resolution Enhancement through
Addition of Solvent to Eluent
The determination of mono-, di- and trimethylamines in the presence of ammonia, alkali (excluding potassium) and alkaline
earth metals can be accomplished by isocratic elution using 10 mM methanesulfonic acid (MSA). Further enhancement of
resolution to allow the determination of the methylamines with potassium present can be accomplished by the addition of a
small amount of solvent to the eluent.
Sample Loop Volume:
6.25 µL (2-mm), 25 µL (4-mm)
Analytical Column:
IonPac CS14 Analytical Column
Eluent:
See Chromatogram
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)
Recycle Mode or 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
Figure 8
Isocratic Elution of Mono-, Di- and Trimethylamines
Isocratic Eluent: 10 mM MSA / 0.3% ACN
CSRS ULTRA: AutoSuppression External Water Mode
Analyte
mg/L
1.
Li
+
0.5
2.
Na
+
2.0
3.
NH
4
+
2.5
4.
Methylamine
10.0
5.
Dimethylamine
20.0
6.
K
+
5.0
7.
Trimethylamine
30.0
8.
Mg
2+
2.5
9.
Ca
2+
5.0
1 mg/L = 1 ppm
Isocratic Eluent: 10 mM MSA
CSRS ULTRA: AutoSuppression Recycle Mode
0
5
10
15
μ
S
0
Minutes
1
2
3
4
5,6
5
15
10
7
8
9
0
5
10
15
μ
S
0
Minutes
1
2
3
4
5
5
10
7
8
9
6
