Figure4
The Allure
™
Basix column offers alternative selectivity for verapamil in the reverse phase mode.
1
LC_0077
RestekCorporation • (800)356-1688 • (814)353-1300 •
Figure5
The Allure
™
Basix column separates metoprolol and an impurity in 10minutes.
LC_0090
0 1 2 3 4 5 6 7 8 9 min.
2
BetaAntagonists
Two of the more common beta antagonists are atenolol
and metoprolol. The analytical techniques cited in some
compendia methods for these compounds use a C18 phase
with ion pairing agents. A simpler approach makes use of
the nitrogen atom on these compounds as a key mechinism
for separation. However, the basic amine groups allow
analysis of these compounds using normal phase separa-
tion with the Allure
™
Basix column.
Because metoprolol is more lipid-soluble than atenolol,
it is more hydrophobic. Therefore, an increase in the organic
composition of the mobile phase actually will enhance
the retention of metoprolol with the Allure
™
Basix phase.
The Allure
™
Basix column performs separation of these
components, provides alternate selectivity to alkyl station-
ary phases, and reveals an impurity in the metoprolol
(Figures 5 and 6).
Column:
Allure
™
Basix
Catalog #:
9161565
Dimensions:
150 x 4.6mm
Particle Size:
5µm
Pore Size:
60Å
Conditions:
Mobile phase:
20mM ammonium
acetate pH 4.5:
acetonitrile (65:35, v/v)
Flow:
1.2mL/min.
Temp.:
25.0°C
Det.:
UV @ 230nm
Peak List:
1. toluene (marker)
2. verapamil HCL
Sample:
Inj.:
1µL
Conc.:
1mg/mL
Solvent:
water:acetonitrile
(70:30, v/v)
0
2 4
6
8 10 12 14 min.
1
Peak List:
1. unknown
2. metoprolol
Sample:
Inj.:
2.5µL
Conc.:
1.5mg/mL
Solvent:
water:methanol
(70:30)
Column:
Allure™ Basix
Catalog #:
9161565
Dimensions:
150 x 4.6mm
Particle Size:
5µm
Pore Size:
60Å
Conditions:
Mobile Phase:
10mM ammonium
formate, pH 2.5:
acetonitrile
(10:90, v/v)
Flow:
1.2mL/min.
Temp.:
25°C
Det.:
UV @ 225nm
2
