IonPac NS1 Manual
Document No. 034024-06
Page 20 of 35
4.1.6 Separation of Alkanolamines Using Ion-Pairing with Suppressed Conductivity (MPIC)
The separation of alkanolamines is also obtained with the use of nonafluoropentanoate ion as the ion-pairing agent. The eluent
is suppressed with a CSRS ULTRA II, using 10 mN boric acid as regenerant. The boric acid is added to increase the ionization
of the ethanolamines, thereby increasing the conductivity. The borate counter ion displaces the hydroxide counter ion from the
fully ionized alkali and alkaline earth metals which reduces the observed conductance for these ions.
Column:
IonPac NS1 (10 µm)
Eluent:
2 mM Nonafluoropentanoicacid / 2% Acetonitrile
Flow Rate:
1.0 mL/min
Inj.Volume:
25 µL
Detection:
Suppressed conductivity, CSRS ULTRA II
AutoSuppression MPIC Mode
Regenerant:
10 mN Boric acid
Peaks:
mg/L
1.
Lithium
0.5
2.
Sodium
2.0
3.
Ammonium
5.0
4.
Potassium
5.0
5.
Monoethanolamine 25.0
6.
Diethanolamine
50.0
7.
Triethanolamine
100.0
8.
Calcium
5.0
9.
Magnesium
2.5
where 1 mg/L= 1 ppm
Figure 6
Separation of Alkanolamines Using
Ion-Pairing with Suppressed Conductivity (MPIC)
