LC_0116
0
5
10
15
20 min.
1
3
2
LC_0100
1
2
3
0 1 2 3 4 5 6 7 8 9 min.
RestekCorporation • (800)356-1688 • (814)353-1300 •
beclomethasone and des-chlorobeclomethasone is reversed
on the Ultra Cyano column compared to the Ultra C18
column, thereby allowing the impurity to elute before the
major component.
The analysis of the contraceptive mixture of ethynyl
estradiol and norgestrel using Allure
™
C18 and Allure
™
Basix
columns demonstrates excellent peak shape and selectivity
towards these compounds, although the elution order is
reversed (Figure 3). Because either column is capable of
separating these compounds, sensitivity and sample matrix
concerns will dictate the selection of the most appropriate
column.
Figure3
The Allure Basix column offers an alternative elution order along with excellent peak shape and selectivity
for a common contraceptive mixture when compared to the Allure C18 column.
Peak List:
1. uracil (marker)
2. norgestrel
3. ethynyl estradiol
Column:
Allure
™
Basix
Catalog #:
9161565
Dimensions:
150 x 4.6mm
Particle Size:
5µm
Pore Size:
60Å
Conditions:
Mobile Phase: water:methanol
(40:60, v/v)
Flow:
1mL/min.
Temp.:
25°C
Det.:
UV @ 220nm
Sample:
Inj.:
5µL
Conc.:
100µg/mL
Solvent:
mobile phase
Column:
Allure
™
C18
Catalog #:
9164565
Dimensions: 150 x 4.6mm
Particle Size: 5µm
Pore Size:
60Å
Conditions:
Mobile Phase: water:methanol
(25:75, v/v)
Flow:
1.0mL/min.
Temp.:
25°C
Det.:
UV @ 220nm
Sample:
Inj.:
5µL
Conc.:
100µg/mL
Solvent:
water:methanol
(40:60)
Conclusion
Factors such as sensitivity, purity, selectivity, and reproduc-
ibility influence column selection when creating a chromato-
graphic method. No one column can provide all the neces-
sary factors for every analysis. The Ultra and Allure™
column series provide a wide range of retention and selectiv-
ity characteristics to create rugged chromatographic meth-
ods. The choice of the best stationary phase must be
determined during the course of method development to
insure the appropriate analytical factors have been opti-
mized.
