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Figure 3
Derivatizing with HFAA yields symmetric peaks but results
in system contamination and a noisy baseline.
Figure 4
A post-derivatization clean up procedure results in sym-
metric peaks and a clean baseline.
Table I
Tailing factor comparison of pretreatments.
Pretreatment
TF Amp
TF Meth TF MDA TF MDMA TF MDEA
Sodium Borate Wash (GC/FID)
2.115
2.837
NA
NA
NA
HFAA Only (GC/FID)
1.010
0.989
NA
NA
NA
HFAA w/Post clean Up (GC/FID)
0.981
0.996
1.007
0.997
0.992
NOTE: A perfectly symmetric peak exhibits a tailing factor of 1.0. Tailing factors shown were generated
using the USP tailing factor calculation.
Incorporating a post conversion/derivatization
clean-up procedure removed derivatization con-
taminants while maintaining chromatographic
quality (Table I), thus reducing the need for frequent
systemmaintenance and extending column lifetime.
These benefits were also seen when samples were
analyzed by GC/MS (Figure 5).
Conclusion
The conversion/derivatization/clean-up procedure
presented here produces symmetric peaks while
reducing the amount of contamination that can
enter the GC system. This method ensures accurate
area count reproducibility, a clean GC system, and
a stable baseline, even for GC/MS work.
GC_PH00975
1. amphetamine
2. methamphetamine
See Figure 1 for conditions.
1. amphetamine
2. methamphetamine
3. MDA
4. MDMA
5. MDEA
See Figure 1 for conditions.
Figure 5
Post-derivatization clean up also
produces symmetric peaks and a stable
baseline when analyzed by GC/MS.
GC_PH00972
Column: Rtx
®
-5MS, 30m, 0.25mm ID, 0.25µm (cat.# 12623)
Sample: 100µg/mL each amphetamine, methamphetamine, MDA,
MDMA, and MDEA extracted from methanol and HFAA derivatized
Inj.: 1µL, splitless (hold 0.5 min.), 3.5mm custom splitless inlet liner
w/IP deacitvated wool; Inj. temp.: 220°C; Carrier gas: helium, constant
flow; Flow rate: 1.25mL/min.; Oven temp.: 70°C (hold 1 min.) to 290°C
@ 15°C/min. (hold 4 min.); Det: MS; Transfer line temp.: 280°C; Scan
range: 43-450amu; Ionization: EI; Mode: scan.
Peak List:
Tailing Factor:
1. amphetamine
1.109
2. methamphetamine
0.992
3. MDA
1.106
4. MDMA
1.068
5. MDEA
1.113
Rtx®-5MS—Low-bleed GC/MS Column (fused silica)
(Crossbond
®
5% diphenyl/95% dimethyl polysiloxane)
ID
df (µm)
temp. limits
length
cat. #
price
0.25mm
0.25
-60 to 330/350°C 30-Meter
12623
Compound
CAS# cat.#
price
HFAA (heptafluorobutyric acid anydride)
10-pk. (10x1g)
336-59-4 35622
25g Flex Tube
336-59-4 35623
Acylation Derivatization Reagents
Solvent
Compound
CAS# Code Conc.
cat.#
(ea.) price
d-amphetamine 51-63-8 PTM 1,000 34020
3,4-MDA HCl
4764-17-4
M 1,000 34070
3,4-MDEA HCl
82801-81-8 M 1,000 34072
3,4-MDMA HCl
42542-10-9 M 1,000 34071
Exempted Drug of Abuse Reference
Materials: Amphetamines & Metabolites
Concentration is µg/mL. Volume is 1mL/ampul.
2
4
6
8
10
12
14
Time (min)
GC_PH00976
1
2
3
4
5
2
4
6
8
10
12
14
Time (min)
1
2
M=methanol
PTM=purge & trap grade methanol