Product Manual for IonPac CS16
Page 48 of 65
5.22.
Gradient Elution of Common Cations and Alkanolamines at 60 °C
This is a methanesulfonic acid gradient from 6 mM to 70 mM, at 0.5 mL/min flow rate, done with an Eluent Generator,
EG40, on the high capacity CS16 cation exchanger at 60 °C. The analytes are the common cations, sodium, ammonium,
magnesium and calcium as well as different monoamines containing alkanol groups, which makes them more hydrophilic.
Under these conditions, sodium partially coelutes with peak #2, 2-Amino-2-(hydroxymethyl)-1,3-propanediol, and potassium
coelutes with peak # 7, 2-methylaminoethanol. No organic solvent was used in the eluent, and temperature and the acid
concentration gradient is used to improve the elution of the larger alkanolamines. The suppressor can be used in the eluent
recycle mode as there is no organic solvent used, however, the suppressor must be placed outside the chromatographic oven
when temperatures exceed 40 °C as they do here.
Column:
IonPac CS16 3-mm Analytical Column (no guard)
Eluent:
6 mM MSA, gradient from 0 to 10 min to
9 mM MSA, gradient from 10 to 30 min to
70 mM MSA
Eluent Source: EG40
Flow Rate:
0.5 mL/min
Inj. Volume:
25 µL
Detection: Suppressed
conductivity
CSRS 300 2-mm outside oven
AutoSuppression Recycle Mode
0
5
1 0
1 5
2 0
2 5
0 .2
0 .9
1 .7
µS
1
2
3
4
5
6
7
8
9
1 0
1 1
1 2
1 3
1 4
1 5
Analyte mg/L
1. Lithium
0.05
2. Sodium
0.20
3. Ammonium
0.42
4. Ethanolamine
0.50
5. Methylamine
0.50
6. Diethanolamine
1.00
7. Potassium
0.50
8. Dimethylamine
1.00
9. Triethanolamine
18.00
10. 5-Amino-1-pentanol
2.00
11. Morpholine
2.00
12. Trimethylamine
1.50
13. Magnesium
0.25
14. Calcium
0.50
15. 2-Diethylaminoethanol
2.00
Figure 31
Gradient Elution of Common Cations and Amines at 60 °C
Document No. 031747-05
© 2010 Dionex Corporation
December 2010
