1
Analysis of Brominated Flame Retardants by GCTOFMS
Peter Gorst-Allman • LECO Africa, Kempton Park, South Africa
Jayne de Vos • NMISA, Pretoria, South Africa
Key Words: BFR, PBDE, flame retardant, POP, Brominated flame retardants,
decabromodiphenylether, decaBDE
Introduction
Brominated Flame Retardants (BFRs) fall into a class of chemical compounds
known as the polybrominated diphenyl ethers (PBDEs). This group is part of
the “new POPs” (persistent organic pollutants), and as such their
determination is of critical importance in environmental analysis.
With the European Union directive restricting the use of pentaBDE and OBDE
in electrical and electronic equipment, more focus is now being placed on
decabromodiphenylether (decaBDE) and its analysis (RoHS Directive
2002/95/EC, Jan 2003). This directive restricts the use of certain hazardous
substances in electrical and electronic equipment, except DecaBDE.
The PBDEs are reported to be extremely stable. However, several studies
have investigated the photolytic lability of the individual congeners from the
commercial products and found that when PBDEs are dissolved in organic
solvents, debromination occurs in the presence of UV light (Eriksson et al.
2001a; Olsman et al. 2002; Tysklind et al. 2001). DBDE breaks down to lower
brominated congeners (nona- to hexa-BDEs). Analytical efforts focus on
keeping the decaBDE intact.
Gas Chromatography coupled to Time of Flight Mass Spectrometry (GCTOFMS) is becoming a pivotal tool for the rapid analysis of environmental
pollutants, offering speed, selectivity and sensitivity. A rapid GC-TOFMS
method for the analysis of PBDEs is described in this note.
Samples
A mixture of brominated flame retardants was purchased from Wellington
Laboratories (BFR-CS5). In total 46 components were present in the standard
solution. A complete list of the components contained in the standards is
shown in Table 3. This Application Note is also available in electronic format
on the LECO Africa website (www.lecoafrica.co.za) in the Application Notes
section. A user library has been created containing mass spectra of all the
components in the standard generated on the Pegasus III instrument used.
Analysis Conditions
2
For this investigation, two approaches were followed:
• Direct injection using a uniliner and a meter retention gap with a 15 m
Rtx-5SilMS column
• Normal liquid injection using an Rtx-1614 column
The Rtx-5SilMS column was initially seleted in order to develop a GC-TOFMS
method for the analysis of PBDEs using direct injection in order to minimize
possible breakdown of the DBDE. The Restek Rtx-1614 column was used
and proved to be highly effective for PBDE analysis, and is stable to 360°C
allowing for facile analysis of even the non-volatile decabromodiphenyl ether
and decabromodiphenylethane.
Table 1. GC-TOFMS conditions for the sample analysis
Detector:
LECO Pegasus III Time of -Flight Mass Spectrometer
Rtx-5SilMS
Rtx-1614
Acquisition Rate:
5 spectra/s
5 spectra/s
Acquisition Delay:
5 minutes
3 minutes
Stored Mass Range:
50 to 1000 u
50 to 1000 u
Transfer Line Temperature:
280ºC
280ºC
Source Temperature:
250ºC
250ºC
Detector Voltage:
-1850 Volts
-1850 Volts
Mass defect:
- 50 mu/100u
- 50 mu/100u
Column :
Rtx-5SilMS, 15 m x 0.25
mm ID, 0.10 µm film
thickness
Rtx-1614, 30 m x 0.25
mm ID, 0.10 µm film
thickness
Column Oven:
80ºC for 2 min, to 295ºC at
12ºC/min, hold for 10 min
100ºC for 3 min, to 320ºC
at 5ºC/min, hold for 15
min
Inlet:
Splitless at 220ºC
Splitless at 300ºC
Injection:
1 µL
1 µL
Carrier Gas:
Helium, 3.0 mL/min
corrected constant flow
Helium, 1.0 mL/min
corrected constant flow
Data processing was performed using the parameters described in Table 2.
Table 2. GC-TOFMS data processing parameters
S/N (Masses):
50:1 (248 328 357 406 485 486 552 564 628 644 722
802 880 960)
1st Dimension Peak Width:
4 s (Rtx-5SilMS & Rtx-1614)
Results and Discussion
The PBDE sample was run using the conditions described in Table 1. After
analysis, data processing was performed using the conditions described in
Table 2. The 46 components present in the sample could be easily located,
and were well separated from each other using both columns.
3
The GCxGC-TOFMS chromatograms showing the selected ions (248, 326,
404, 486, 564, 644, 722, 802, 880, 960) for the PBDE analysis are shown in
Figures 1 and 2.
Figure 1. GC-TOFMS results (selected ions) for the BFR sample using the
Rtx-5SilMS column
123
4
5
6
7
8
910
11 12
15 16
17 19
20 22
24
27 28
31 32
35
36 39 41
42
44
45
46
25000
20000
15000
10000
5000
0
Time (s)
400
600
248
328
406
800
486
564
1000
644
722
802
1200
880
960
1400
Figure 2. GC-TOFMS results (selected ions) for the BFR sample using the
Rtx-1614 column
4
12 3
4
5
6
7
8 9 10
1113
15 16
17 19
20 22
24 26 2729 30
32
35
36 39 41
42 44
45
46
25000
20000
15000
10000
5000
0
Time (s)
1000
248
328
357
1500
406
485
486
2000
552
564
628
2500
644
722
802
880
3000
960
The BFR retention times, and the library matches for the different compounds
are shown in Table 3 below.
Table 3. Retention times for the BFRs in the sample
Peak
#
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
Name
Bromodiphenylether
Bromodiphenylether
Bromodiphenylether
Dibromodiphenylether
Dibromodiphenylether
Dibromodiphenylether
Tribromodiphenylether
Tribromodiphenylether
Tribromodiphenylether
Benzene, pentabromoethyl‐
(PBEB)
Benzene, hexabromo‐ (HBB)
Tetrabromodiphenylether
Tetrabromodiphenylether
Tetrabromodiphenylether
Tetrabromodiphenylether
Tetrabromodiphenylether
R.T. (s) Similarity
817.09
966
834.69
942
854.09
929
1077.49
979
1144.69
954
1221.29
945
1346.29
944
1449.29
959
1484.69
909
1536.29
895
1669.09
1692.49
1702.09
1731.89
1764.69
1816.89
883
951
939
929
932
913
Weight
248
248
248
326
326
326
404
404
404
496
S/N
1657
1079
1153
3333
2562
631
1423
1050
839
305
546
482
482
482
482
482
344
1005
1209
733
675
420
5
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
Pentabromodiphenylether
Pentabromodiphenylether
Pentabromodiphenylether
Pentabromodiphenylether
Pentabromodiphenylether
2,2',4,4',5,5'‐Hexabromobiphenyl
(BB 153)
Hexabromodiphenylether
Hexabromodiphenylether
Hexabromodiphenylether
Hexabromodiphenylether
Hexabromodiphenylether
Hexabromodiphenylether
Hexabromodiphenylether
Heptabromodiphenylether
Heptabromodiphenylether
Heptabromodiphenylether
1,2‐Bis(2,4,6tribromophenoxy)ethane
(BTBPE)
Heptabromodiphenylether
Heptabromodiphenylether
Octabromodiphenylether
Octabromodiphenylether
Octabromodiphenylether
Octabromodiphenylether
Octabromodiphenylether
Octabromodiphenylether
Nonabromodiphenylether
Nonabromodiphenylether
Nonabromodiphenylether
Decabromodiphenylether
Decabromodiphenylethane (DBDPE)
1909.69
1926.49
1959.89
2049.09
2063.09
2095.69
928
940
943
920
945
901
560
560
560
560
560
622
471
544
403
332
208
318
2099.29
2165.89
2193.09
2210.69
2254.69
2286.09
2288.29
2329.09
2360.09
2409.89
2417.29
921
942
878
932
926
660
863
892
914
888
842
638
638
638
638
638
638
638
716
716
716
682
423
352
300
300
237
131
241
403
406
367
190
2435.89
2477.09
2561.89
2576.49
2580.89
2606.49
2620.89
2656.89
2798.29
2816.89
2855.09
3108.49
3323.12
900
945
898
874
919
919
851
852
925
926
915
912
605
716
716
794
794
794
794
794
794
872
872
872
950
962
285
282
303
119
233
237
228
129
381
340
255
1222
79
6
Conclusions
Using the 15m Rtx-5SilMS column with direct injection and the analytical
conditions shown Table 1, all 46 PBDE components were adequately
separated. The DBDE remained intact and could be easily identified.
Using the Rtx-1614 column and the analytical conditions described in Table 1,
all 46 components of the BFR standard mixture could be separated and
identified with excellent library matches.
At this stage no limits of detection (LODs) for these compounds have been
obtained, but these will be measured in the future. It should be appreciated
that LODs are matrix dependant, and consequently the LODs which will be
measured for the combined BFR standard without matrix interference may
differ from those possible in real world samples.