18
For more information, or to download product instructions,
Perfluoro Acid Anhydride (TFAA, PFAA
and HFAA)
Ours are high-purity, ideal for preparing fluoracyl
derivatives.
C R
O
C O
O
R
R
Name
M.W.
b.p.
d
20
4
CF
3
TFAA
210.0
39.5-40.5˚C
1.490
C
2
F
5
PFAA
310.0
74˚C
1.571
C
3
F
7
HFAA
410.0
106-107˚C
1.665
Fluorinated anhydrides are used to prepare fluoracyl
derivatives for GC/MS, they produce stable volatile
derivatives for FID and ECD techniques.
PROTOCOL 1
Preparing fluoracyl derivatives of amines and alcoholic compounds on
a submicrogram scale for ECD.
1. Combine < 50 ng sample dissolved in 500 µl benzene and 100 µl 0.05 M TEA
in benzene in a 5.0 ml Thermo Scientific Reacti-Vial Small Reaction Vial.
2. Add 10 µl Acid Anhydride.
3. Cap vial, heat at 50°C for 15 minutes, then cool.
4. Add 1 ml water, cap vial and shake 1 minute.
5. Add 1 ml 5% aqueous ammonia, cap vial and shake 5 minutes.
6. Centrifuge.
7. Inject 1-10 µl benzene phase for ECD.
NOTE:
Use 250 µg for FID. Excess TEA is required for quantitative conversion
of amines. TEA does cause disturbances in the chromatogram at high EC
sensitivity. The benzene is used as sample solvent and TEA solvent should
be dry, as water will compete for the anhydride during reactions. The
amount of anhydride used in the procedure (10 µl) is 25% more than
necessary for a complete reaction – even if the 0.5 ml benzene used is
water-saturated.
PROTOCOL 2
Preparing fluoracyl derivatives of phenols for FID and ECD.
For Flame Ionization Detection:
1. Combine 1 mg sample dissolved in 0.5 ml benzene and 200 µl 0.1 M TEA in
benzene.
2. Add 25 µl Acid Anhydride.
3. Cap vial and let react at room temperature for 15 minutes.
4. Add 0.5 ml 1 M phosphate buffer, pH 6.0, and shake for 30 seconds.
5. Centrifuge.
6. Separate organic phase. Analyze by GC.
For Electron Capture Detection:
1. Combine 0.5 ml benzene containing the sample and 10 µl TEA in benzene
in a 5 ml Thermo Scientific Reacti-Vial Small Reaction Vial.
2. Add 10 µl HFAA.
3. Cap vial and let react at room temperature for 10 minutes.
4. Add 0.5 ml 1 M phosphate buffer, pH 6.0, and shake 30 seconds.
5. Centrifuge; analyze 2 µl benzene phase by GC.
NOTE:
Excess anhydride and acid are removed by the aqueous extraction.
No ECD disturbances from the water or other constituents. HFB-esters of
phenols are stable in the presence of water (with aqueous phase at
pH ≤ 6.0). Alkaline extraction with reagents, such as aqueous ammonia,
decomposes the HFB ester. A pH ≤ 6.0 maintains the TEA catalyst in the
protonized form. TEA in the unprotonized form will catalyze decomposition
of the esters.
Ordering Information
Product # Description
Pkg. Size
✖
TS-67363
TFAA
100 g
(Trifluoroacetic Acid Anhydride)
bottle
TS-65193
PFAA
10 x 1 ml
(Pentafluoropropionic Acid Anhydride)
ampules
✖
TS-65192
PFAA
25 g
bottle
✖
TS-65191
PFAA
100 g
bottle
TS-63164
HFAA
10 x 1 ml
(Heptafluorobutyric Acid Anhydride)
ampules
✖
TS-63163
HFAA
25 g
bottle
✖
TS-63162
HFAA
100 g
bottle
✖
Additional hazardous handling charge.
Thermo Scientific Acylation Reagents
