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Figure 1
Achieve good peak shape and response of sympathomimetic amines using an
Rtx®-5 Amine column.
Analyzing ppm levels of basic compounds, such as
amines, by gas chromatography (GC) often requires
derivatization of the sample or column priming to
improve peak shape and sensitivity. Restek’s innova-
tive Rtx®-5 Amine capillary column features a
unique deactivation technology that reduces adsorp-
tion and peak tailing for a wide variety of amines
and other basic compounds without derivatizing or
priming, even at low ppm concentrations.
Many drug compounds are basic because they con-
tain amine functional groups. The Rtx ®-5 Amine col-
umn can analyze many of these drug compounds
successfully without costly derivatization. The ion
trap GC/MS analysis of underivatized sympath-
omimetic amines on the Rtx®-5 Amine column
shows excellent peak shapes and low column bleed,
making it ideal for trace-level analyses (Figure 1).
Ethyleneamines are used as chemical intermediates
and solvents, and in the manufacture of chelating and
emulsifying agents. Analyzing trace impurities of these
basic compounds is difficult because most capillary
columns will adsorb them. The Rtx®-5 Amine column
is uniquely deactivated to be ideal for the analysis of
ppm-level basic impurities in ethyleneamines and
piperazines (Figure 2). Notice that tailing is minimal
and exceptional response is achieved.
Because some adsorption of basic compounds can
occur in the injection port, further improvements
to the peak shape and response of amines can be
obtained by using base-deactivated inlet liners.
Base-deactivated inlet liners are available for most
GC configurations. This ensures a completely inert
sample pathway from injection port to detector. For
consistently successful amine response, use this
base-deactivated system and the Rtx®-5 Amine
column.
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GC_CH00298
30m, 0.25mm ID, 0.50µm Rtx-5
Amine (cat.# 12338); Sample: 3.0µL
split injection of ethyleneamine indus-
trial sample with on-column concen-
tration ~5-80ng.; Oven temp.: 40°C
(hold 4 min.) to 315°C @ 10°C/min.
(hold 5 min.); Inj. & det. temp.:
315°C; Carrier gas: hydrogen; Linear
velocity: 43cm/sec. set @ 40°C;
FID sensitivity: 6.4 x 10-11 AFS;
Split ratio: 20:1
1. isopropanol
2. monoethanolamine
3. ethylenediamine
4. piperazine
5. diethylenetriamine
6. aminoethylethanolamine
7. aminoethylpiperazine
remaining impurities consist of ethyle-
neamine and piperazine derivatives
Figure 2
The Rtx®-5 Amine column accurately analyzes trace impurities in ethyleneamines and piperazines.
Rtx® -5 Amine GC
Column
by Neil Mosesman, GC Columns Product Marketing Manager
✔ Deactivated tubing reduces sample adsorption.
✔ Eliminates costly derivatization procedures.
✔ Offers low bleed and excellent peak shape.
Ideal for Trace-Level Analyses of Basic Compounds
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1. phenylethylamine
2. amphetamine
3. phentermine
4. methamphetamine
5. fenfluramine
6. mephentermine
7. cathinone
8. phenylpropanolamine
9. methcathinone
10. nicotine
11. ephedrine
30m, 0.25mm ID, 0.50µm Rtx-5 Amine
(cat.# 12338); Injections performed in the
split mode with a split vent flow rate of
45mL/min.; Analysis performed using a
Varian 3400 GC coupled with a
Varian Saturn 2000 MS detector;
Conc.: 1mg/mL; Oven temp.: 100°C to
310°C @ 10°C/min.; MS scan
range: 40-600 amu. Ionization was
performed in the EI Auto mode.
7.5 10 12.5 15 17.5 min. 5
12. pseudoephedrine
13. phenmetrazine
14. phendimetrazine
15. methylenedioxyamphetamine
16. diethylpropion
17. methylenedioxymethamphetamine
18. methylenedioxyethylamphetamine
19. 4-methyl-2,5-dimethoxyamphetamine
20. phenylephrine
21. caffeine
22. benzphetamine
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GC_PH00438
sample courtesy of a
Restek customer