346 / 413
Figure 2
Overall, the Allure' Biphenyl column is the best choice for
assaying the tetracycline anti biotic s.
tetracycline
Column:
Cat.
# :
Dimensions:
Particle size:
Pore size:
Allure" Biphenyl
9166565
150x
4.6
mm
51l~
60A
degradatioD
'--...
~
_ _
I
.
,
10
Min.
tetracycline
Column:
Cat.
#:
Dimensions:
Particlesize:
Poresize:
Allure" PFP Propyl
9169565
150
x4.6
mm
51llT'
60A
degradationpeak
LCPH0346
I
i
)
1
•
e
S
10
12
MOR
tetracycline
Column:
Ultra C18
Cat.
# :
9174565
Dimensions:
150 x4.6
mm
Particle size:
51l1lJ
Pore size:
100A
degradationpeak
I
I
i
i
i
1.0
2.0
'.0
.. ..
Min,
Sample:
Inj.:
51ll
Cone.:
100llg/ml
each component
Sample diluent: methanol
Conditions:
Mobile phase: 20mM ammoniumphosphate (pH 2.5):acetonitrile, 80:20
Flow:
I mL/min.
Ternp.:
ambient
DeL:
UV @
254
nm
2006
vol. 1
• 13 •
Table 2
Allure' Biphenyl, Alture' PFP Propyl,
and Ultra (18 columns provide excellent
repeatability.
Retention
capacity
USP
PeakArea
Time min.) Factor
(k')
Tailinll_
Allure~
B
ip~!l~1
bestchoice fortetracycline antibiotics
Mean
2509475
7.08
5.68
1.06
Std. Dev.
36397.39
0.02
0.03
0.01
%RSD
1.45
0.36
0.45
0.49
Allure" PFP
PrllP~I
---::-:__
---:--:c:-_ _ -:-::::.Mean
2483972
9.52
8.12
1.28
Std. Dev.
22202.94
0.04
0.04
0.01
%RSD
0.89
0.45
0.53
0.43
Ultra Cl8
Mean
2399803
5.13
3.73
1.21
Std. Dev.
21171.76
0.02
0.02
> 0.00
%RSD
0.88
0.33
0.45
0.34
stationary phase exhibits
n-n
bonding with the
ring structures of the tetracyclines, and the embed
ded polarity of the fluorinated Allure " PFP Propyl
phase interacts with tetracycline moieties. Either of
these separation mechanisms increases retention,
compared to a mechanism based on hydrophobic
ity, as exhibited by the alkyl chain of a Ci S phase.
Tetracycline drug products are produced under
cGMP protoco ls and, therefore, manufacturers are
required to use validated or compendial methods,
either of which require the completion of system
suitabi lity criteria (e.g., tailing factors, capacity fac
tors, and repeatability). Consequently, we further
evaluated the three stationary phases that pro
duced the best initial results, using system suitabil
ity criteria, by assaying tetracycline.
Overall, all three columns provided excellent
repeatability Crable 2). The Allure?' PFP Propyl
column exhibited the greatest retention and capac
ity for the analytes, but exhibited the highest
degree of peak tailing under these conditions
(Figure 2). The Ultra Ci S column also exhibited a
high degree of peak tailing, and the weakest ana
lyte retention (Figure 2).Altering the mobile phase
likelywould improve peak shape, but capacity fac
tors would suffer accordingly. The Allure ?"
Biphenyl column proved to be the best overall
choice for the tetracyclines - it exhibited good
capacity, high selectivity, and the least peak tailing
(Figure 2).
By selecting the stationary phase that provides the
best selectivity and efficiency for tetracycline ana
lytes - the Allure?" Biphenyl phase - analysts can
exercise more control over separation and other
method condit ions, ultimately creating a simple,
rugged, and selective method.
Allure™
Biphenyl Column
Slim Column, 4.6mm
cat.
#
150mm
9166565
Website :
www.chromtech.net.auE-mail :
info@chromatech.net.auTelNo : 03 9762 2034 . . . in AUSTRALIA