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2007.01
Ultra Aqueous C18 Columns (USP L1)
5µm Column, 2.1mm
cat. #
price
150mm
9178562
$385
150mm (with Trident
™
Inlet Fitting)
9178562-700
$400
ordering
note
For guard cartridges for these columns, visit our website at
www.restek.com.
Syringe Filters
• Color coded for easy identification.
• Reusable storage container.
Size
Porosity Color
qty.
cat.#
price
Nylon
25mm 0.45µm pink 100-pk.
26149
$92
25mm 0.45µm pink 500-pk.
26203
$375
The Ultra Aqueous C18 phase proved ideal for
resolving the complex tea matrix, as shown by the
large number of peaks in Figure 1. The resolving
power of this chromatographic system, in combi-
nation with the LECO Unique® TOF Mass
Spectrometer, allow the analyst to both extract
data for specific compounds of interest and man-
ually inspect spectra for other compounds, includ-
ing phenolic glycosides and esters of phenolic acid.
If you are analyzing antioxidants in tea, or other
complex mixtures of compounds, an Ultra
Aqueous C18 column gives you the reliable results
you need, without restricting your ability to use
the mobile phase composition that works best for
your application.
For information about the LECO Unique
®
TOFMS, please visit the LECO
website:
www.leco.com1 Free radical damage is implemented in many disease models, includ-
ing cancer, in many degenerative illnesses, and in the aging process.
2 When the long, hydrophobic alkyl chain of a conventional C18 station-
ary phase is exposed to a highly aqueous mobile phase it folds down
on itself, causing loss of retention. A prolonged equilibration time in a
high organic solution is needed to restore the phase. The Ultra
Aqueous C18 stationary phase is not susceptible to phase collapse –
not even in mobile phases with very highly aqueous content.
Table 1
Phenolic compounds of interest.
Compound
[M-H]-
gallocatechin-3-gallate
457.206
catechin
289.154
epigallocatechin-3-methyl gallate
471.208
epicatechin di-gallate
609.318
epicatechin-3-gallate
441.208
catechin gallate
Note: m/z 441.2 can be either epicatechin-3-gallate or catechin gallate.
Figure 3
Spectra of phenolic compounds identified in the tea extract.
Sample:
Inj.:
10µL
Conc.:
15g tea extracted
w/ 200mL + 20mL
methanol
Sample diluent: methanol
Column:
Ultra Aqueous C18
Cat.#:
9178562
Dimensions:
150 x 2.1 mm
Particle size:
5µm
Pore size:
100Å
Conditions:
Mobile phase:
A: 0.15% formic
acid in water;
B: 0.15% formic
acid in
acetonitrile (v/v)
Time
(min.)
%B
0
5
60
95
Flow:
0.3mL/min.
Temp.:
ambient
Det.:
Leco Unique
®
LC-TOFMS
ESI voltage:
-3500 V
Desolvation
temp.:
300°C
Nebulizer
pressure:
375 kPa
Desolvation gas: 7000 cc/min.
Interface temp.: 100°C
Nozzle:
-80 V
Data acquisition: 3.13 spectra/sec.
A) quercitin dicoumaryl glycoside
B) epigallocatechin 3-methyl gallate
D) gallocatechin-3-gallate
C) caffeic acid ester
E) catechin
LC_FF0425G
LC_FF0425F
LC_FF0425E
LC_FF0425C
LC_FF0425D
See our catalog or website for other sizes and materials.
thank
you
Instrument provided courtesy
of
LECO Corporation.
www.leco.com