IonPac NS1 Manual
Document No. 034024-06
Page 17 of 35
4.1.3 Separation of Aliphatic Sulfonic Acids by Ion-Pairing with Suppressed Conductivity (MPIC)
Ion-pairing can provide excellent selectivity for surface active analytes such as surfactants. The separation of aliphatic sulfonic
acids on the IonPac NS1 analytical column can be achieved using tetrabutylammonium ion as the ion-pairing agent with
conductivity detection. The eluent is suppressed with an ASRS ULTRA II augmented with 10 mN sulfuric acid regenerant.
Aliphatic sulfonic acids are UV transparent, but well detected by suppressed conductivity.
Column:
IonPac NS1 (10 µm)
Eluent:
2 mM Tetrabutylammoniumhydroxide,
24% to 48% Acetonitrile in 10 min
Flow Rate:
1.0 mL/min
Injection Loop:
50 µL
Detection:
Suppressed conductivity, ASRS ULTRA II
AutoSuppression MPIC Mode
Regenerant:
10 mN Sulfuric acid
Peaks:
mg/L
(as the acid forms)
1.
Methanesulfonic acid
5.0
2.
1-Propanesulfonic acid
8.6
3.
1-Butanesulfonicacid
8.7
4.
1-Hexanesulfonicacid
8.8
5.
1-Heptanesulfonic acid
8.9
6.
1-Octanesulfonicacid
8.9
7.
1-Decanesulfonicacid
9.1
where 1 mg/L= 1 ppm
Figure 3
Separation of Aliphatic Sulfonic Acids by Ion-Pairing with Suppressed Conductivity (MPIC)
