Product Manual for IonPac CS16
Page 36 of 65
5.12.
Separation of Methylamines, Group I and Group II Cations and Ammonium at Room
Temperature
The chromatograms below were obtained at room temperature, and the eluent concentration adjusted for optimized
separations. The analytes consisted of a mixture of the common inorganic cations, ammonium plus methyl-, dimethyl- and
trimethylamine. Here, ammonium and methylamine, peaks number 3 and 4, are well resolved from each other. By increasing
the eluent concentration (bottom chromatogram) the run time is decreased to about 15 minutes with improved amine peak
shapes. See Section 5.15, “Amine Selectivity with Common Cations at 65 °C,” for improved chromatography of
trimethylamine.
Column:
IonPac CS16 5-mm Analytical Column (no guard)
Sample Volume:
25 µL Loop
Eluent: See
Chromatogram
Eluent Flow Rate:
1.0 mL/min
Temperature:
Room Temperature (approximately 22 °C)
SRS Suppressor:
Cation Self-Regenerating Suppressor 300 (4-mm) in
AutoSuppression Recycle Mode
or MMS Suppressor:
Cation MicroMembrane Suppressor, CMMS 300 (4-mm)
MMS Regenerant:
TBAOH
MMS Mode:
Displacement Chemical Regeneration (DCR)
Expected Background Conductivity:
< 2 µS
Storage Solution:
Eluent
28 mM Methanesulfonic acid (MSA)
0
5
10
15
20
25
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
1.1
9
8
7
6
0.2
µS
1.0
10
0
15
Minutes
5
20
25
5
4
3
1
2
Analyte mg/L
1. Lithium
0.05
2. Sodium
0.20
3. Ammonium
0.30
4. Methylamine
0.50
5. Dimethylamine
1.00
6. Potassium
0.50
7. Magnesium
0.25
8. Trimethylamine
1.50
9. Calcium
0.50
where 1 mg/L = 1 ppm)
44 mM Methanesulfonic acid (MSA)
0
5
10
15
20
25
0.2
0.4
0.6
0.8
1.0
1.2
1.4
9
8
7
6
0.1
µS
1.4
10
0
15
Minutes
5
20
25
5
4
3
1
2
Analyte mg/L
1. Lithium
0.05
2. Sodium
0.20
3. Ammonium
0.30
4. Methylamine
0.50
5. Magnesium
0.25
6. Dimethylamine
1.00
7. Potassium
0.50
8. Calcium
0.50
9. Trimethylamine
1.50
where 1 mg/L = 1 ppm )
Figure 21
IonPac CS16 5-mm Methylamine Selectivity with Common Cations Using Two Different Eluents
Document No. 031747-05
© 2010 Dionex Corporation
December 2010
