ADV01-05_1-298

79 / 298

• 5 •
Several factors are important when designing a tri-
fluoropropyl polysiloxane (TFP) stationary phase
(i.e., Restek's Rtx®-200 columns): bleed level,
inertness, and efficiency. In order to obtain a low
bleed level and high thermal stability, it is neces-
sary to apply a suitable deactivation to the fused
silica tubing before coating it with the stationary
phase. The deactivation modifies the fused silica
surface so that it is more compatible with the sta-
tionary phase, otherwise the stationary phase will
not coat evenly and will not bond, or link to, the tubing wall. Other manufacturers’ “200-type phases” have this
problem and, as a result, suffer from low thermal stability. However, Restek designed a deactivation layer that is
matched to the TFP phase, so you get low bleed levels and thermal stability to 360°C.
Inertness also can be a function of the deactivation chemistry. Restek tests all Rtx®-200 columns using compounds
that are highly susceptible to on-column breakdown and would indicate a problem with column inertness. Testing
with a quality assurance mixture including reactive phenolics, anilines, and alcohols ensures that each Rtx®-200 col-
umn has the inertness to function at high performance levels.
Finally, efficiency is a measure of the interaction between the compounds in the sample and the stationary phase. If
there is a high resistance to mass transport in the stationary phase, then the compounds elute as broad peaks in the
chromatogram and resolution is negatively effected. The Rtx®-200 columns maintain a high efficiency, resulting in
peak widths that are similar to those obtained with the Rtx®-1 column—one of the most efficient phases available.
While other manufacturers struggle with “200-type” phases that have poor efficiency, inertness, and thermal stability,
Restek customers can expect to achieve the unique selectivity of TFP phases without compromising these other
important chromatographic conditions.
Restek TFP Phase
Low Bleed with a High Degree of
Inertness and Efficiency
by Frank Dorman, Ph.D., Environmental Innovations Chemist
CF3
C2 H4
Si
CH3
0
TFP phase structure of the
Rtx®-200 column.
Analytical Gas Chromatography, 2nd Ed.
W. Jennings, E. Mittlefehldt and P. Stremple,
Academic Press, 1997, 389pp.
cat.# 21362, (ea.)
Basic Gas Chromatography
H. M. McNair and J. M. Miller, John Wiley, 1997,
200pp.
cat.# 21366, (ea.)
Capillary Gas Adsorption Chromatography
V. G. Berezkin and J. de Zeeuw, Wiley-VCH, 1998,
320pp.
cat.# 21097, (ea.)
Chiral Chromatography
T. E. Beesley and R. P. W. Scott, John Wiley, 1999,
506pp.
cat.# 21094, (ea.)
Environmental Sampling and Analysis Lab
Manual
M. Csuros, CRC Press LLC, 1997, 373pp. (softcover)
cat.# 21375, (ea.)
GC/MS in Clinical Chemistry
P. Gerhards, U. Bons, J. Sawazki, J. Szigan and A.
Wertmann, Wiley-VCH, 1999, 241pp.
cat.# 21096, (ea.)
Handbook of Chemistry and Physics, 81 st Ed.
D. R. Lide, CRC Press LLC, 2000, 2480pp.
cat.# 21376, (ea.)
Handbook of Environmental Analysis
P. Patnaik, CRC Press LLC, 1997, 584pp.
cat.# 21381, (ea.)
HPLC Columns. Theory, Technology, and
Practice
U. D. Neue, John Wiley, 1997, 393pp.
cat.# 21368, (ea.)
HPLC in Enzymatic Analysis, 2nd Ed.
E. F. Rossomando, John Wiley, 1998, 451pp.
cat.# 21364, (ea.)
Liquid Chromatography, Essential Data
D. Patel, John Wiley, 1997, 146pp. (softcover)
cat.# 21372, (ea.)
The Merck Index, 12th Ed.
S. Budvari, Merck, 1996, 2240pp.
cat.# 21383, (ea.)
New Reference Texts
For GC, GC/MS, HPLC, & More!
by Jack Crissman, Training & Education Manager
Modern Chromatographic Analysis of
Vitamins, 3rd Ed.
A. P. De Leenheer, W. E. Lambert and J. F. Van
Bocxlaer, Marcel Dekker, 2000, 616pp.
cat.# 21092, (ea.)
Molecular Basis of Chromatographic
Separation
E. Forgacs and T. Cserhati, CRC Press LLC, 1997,
243pp.
cat.# 21378, (ea.)
Practical High-Performance Liquid
Chromatography, 3 rd Ed.
V. R. Meyer, John Wiley, 1999, 338pp. (softcover)
cat.# 21095, (ea.)
Practical HPLC Method Development, 2 nd Ed.
L. R. Snyder, J. J. Kirkland and J. L. Glajch, John
Wiley, 1997, 765pp.
cat.# 21363, (ea.)
Practical Introduction to GC-MS Analysis
with Quadrupoles
M. Oehme, Wiley-VCH, 1999, 195pp. (softcover)
cat.# 21098, (ea.)
Practical Problem Solving in HPLC
S. Kromidas, Wiley-VCH, 2000, 178pp. (softcover)
cat.# 21099, (ea.)
Visit our website at
for details on these and other
educational materials