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some differences between Ultra Aqueous C18 and
Ultra IBD columns, however. Note that the elution
orders in Figure 3B are different, demonstrating
significant differences in selectivity. Also, the mal-
onic acid peak tails on the Ultra IBD column. We
believe this is because malonic acid has two car-
boxylic acid groups—several dicarboxylic acids tail
on Ultra IBD columns and similar columns.
Finally, we used the same 100% aqueous mobile
phase to evaluate selectivity and retention for mix-
tures containing both an acid (ascorbic
acid/Vitamin C) and a base (thiamin/Vitamin B1).
Note in Figure 3C that Ultra Aqueous C18 and Ultra
IBD columns produce opposite elution order, again
demonstrating their complementary selectivity. Of
several columns evaluated from various manufac-
turers, the Ultra Aqueous C18 column was the only
column to exhibit significant retention of thiamin.
This is consistent with the enhanced retention of
pyridine shown in Figure 3A. Thiamin is barely
retained by an Ultra IBD column, using the uracil
peak in Figure 2 as the measure of column void
volume (t
0
).
Highly base-deactivated Ultra Aqueous C18 and
Ultra IBD columns are powerful tools for analyzing
polar compounds by reversed phase HPLC. They
offer alternate selectivity to each other, as well as to
conventional C18 stationary phases. Their second-
ary polar functionalities enhance retention of polar
analytes, contribute to their unique selectivity, and
make them compatible with a complete spectrum of
mobile phase compositions, from 100% organic to
100% aqueous. An Ultra Aqueous C18 column is
the better choice for small dicarboxylic acids, or
for maximum retention of bases in a highly aque-
ous mobile phase.
Figure 3
Ultra IBD and Ultra Aqueous C18 columns share important characteristics.
Ordering Information
| Ultra Aqueous C18 5µm Columns
1.0mm ID
2.1mm ID
3.2mm ID
4.6mm ID
Length
cat.#
cat.#
cat.#
cat.#
30mm
9178531
9178532
9178533
9178535
50mm
9178551
9178552
9178553
9178555
100mm
9178511
9178512
9178513
9178515
150mm
9178561
9178562
9178563
9178565
200mm
9178521
9178522
9178523
9178525
250mm
9178571
9178572
9178573
9178575
Ordering Information
| Ultra IBD 5µm Columns
1.0mm ID
2.1mm ID
3.2mm ID
4.6mm ID
Length
cat.#
cat.#
cat.#
cat.#
30mm
9175531
9175532
9175533
9175535
50mm
9175551
9175552
9175553
9175555
100mm
9175511
9175512
9175513
9175515
150mm
9175561
9175562
9175563
9175565
200mm
9175521
9175522
9175523
9175525
250mm
9175571
9175572
9175573
9175575
Column:
Ultra IBD
Ultra Aqueous C18
Ultra Aqueous C18
Catalog #:
9175565
9178565
9178565
Dimensions:
150 x 4.6mm
150 x 4.6mm
150 x 4.6mm
Particle Size:
5µm
5µm
5µm
Pore Size:
100Å
100Å
100Å
LC_0232
Peak List:
Conc.
1. uracil
50µg/mL
2 pyridine
0.1µL/mL
3. phenol
1.86mg/mL
LC_0230
LC_0231
Sample:
Inj:
5µL
Solvent: mobile phase
Mobile phase:
A: 20mM potassium phosphate, pH 7.0
B: acetonitrile
Isocratic: 20%B
Flow:
1.0mL/min.
Temp.:
ambient
Det.:
UV @ 254nm
2
1
2
3
Sample:
Inj.:
10µL
Solvent:
mobile phase
Mobile Phase:
A: 50mM potassium phosphate, pH 2.5
Isocratic: 100%A
Flow:
1.0mL/min
Temp.:
ambient
Det.:
UV @ 210nm
Peak List
Conc. (mg/mL)
1. glycolic acid
2.0
2. lactic acid
3.3
3. acetic acid
2.1
4. malonic acid
1.8
Column:
Ultra IBD
Ultra Aqueous C18
Catalog #:
9175565
9178565
Dimensions:
150 x 4.6mm
150 x 4.6mm
Particle Size:
5µm
5µm
Pore Size:
100Å
100Å
LC_0228
LC_0229
Column:
Ultra IBD
Ultra Aqueous C18
Catalog #:
9175565
9178565
Dimensions:
150 x 4.6mm
150 x 4.6mm
Particle Size:
5µm
5µm
Pore Size:
100Å
100Å
Peak List:
Conc. (mg/mL)
1. thiamin
2.5
2. ascorbic acid
2.5
Sample:
Inj.:
1.0µL
Solvent: mobile phase
Mobile Phase:
A: 50mM potassium phosphate, pH 2.5
Isocratic: 100%A
Flow:
1.0 mL/min.
Temp.:
ambient
Det.:
UV @ 254nm
A) Excellent Deactivation for Bases
B) Compatible with 100% Aqueous
Mobile Phases
C) Complementary Selectivity
1
2
LC_0226
LC_0227
for
more
info
For our complete line of HPLC
columns and HPLC accessories,
request the
2003
Chromatography Products Guide
(lit. cat.# 59473)
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