Special Issue

Polymer Materials Technology

Determination of Additives in Polymeric Material
by Pyrolysis-GC/MS/FPD Analysis
Kenji Iizuka*

Polymeric materials include various additives according to the demand characteristics required. It is important to conduct the qualitative and the quantitative analysis of these additives for the purposes of the product design and the quality control. On the other
hand, the demand characteristics of polymeric materials have become more sophisticated andcomplicated in recent years, leading to the improvement and the development of additives, thus,increasing the number of cases where the conventional technology is not sufficient for the analysis. Through the usage of pyrolysis-GC (Gas Chromatograph)/MS (Mass Spectrometer) /FPD
(Flame Photometric Detector) system with purged splitter installed at the end of the column during
the analysis of additives in polymeric materials, which enables the simultaneous detection throughMS and FPD, we were able to more easily identify the additives which included phosphorus andsulfur in their structure, as compared with the conventional pyrolysis-GC/MS method.
Consideration to the determination of the precision was also given, and it was found that theresults were better than those using MS detectors.

ABSTRACTINTRODUCTION
1.1. INTRODUCTION
Polymeric materials include various additives according
to the demand characteristics required, for instance, theimprovement of the formability, the physical property, thefunctionality or the durability. It is important to conduct thequalitative and the quantitative analysis of these additives
for the purposes of the product design and the quality
control. On the other hand, the demand characteristics ofpolymeric materials have become more sophisticatedand complicated in the recent years, leading to theimprovement and the development of additives, increasing the number of cases where the conventional technology is not sufficient for the analysis. For example, thepyrolysis-GC/MS analysis is a very useful method for
additives in polymeric materials, because pretreatment
like the solvent extraction is not necessary and enable thedirect measurement of a small sample. However, it has
some difficulties in identifying the original additives
according to decomposing of the additives on pyrolysis
condition, or masking the additive component from thedecomposed materials by a matrix polymer.
When using pyrolysis-GC(Gas Chromatograph)/MS(Mass Spectrometer) /FPD (Flame Photometric Detector)
system with a purged splitter installed at the end of thecolumn during the analysis of additives in polymericmaterials, we can enable the simultaneous detection
through MS and FPD. Since we were able to identify moreeasily additives which included phosphorus and sulfur intheir structure, we would like to introduce the analysis indetail 1).

ANALYSISOF
OFAN
AN ANTISTATICANTISTATIC AGENT
2.2. ANALYSISAGENT
POLYCARBONATE BY THE CONVENININPOLYCARBONATEBY THEMETHODCONVENTIONAL METHODTIONALWe analyzed an antistatic polycarbonate pellet in the marketplace to identify the additives in the polymer by theconventional method of infrared spectrometry and thereactive pyrolysis-GC/MS.
2.1 Infrared Spectrometry
The infrared absorption spectrum measured by the attenuated total reflection (ATR) method using Fouriertransform infrared spectrometer (Nicolet Magna 550) witha single bounce ATR attachment (SensIR Technologies
DuraScope)
The result is shown in Figure 1 and there is no difference between the antistatic polycarbonate and the reference polycarbonate. We could not identify absorption
spectrum derived from an antistatic agent.

* Research & Development Div.
Polymer Materials R&D Laboratories

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Determination of Additives in Polymeric Material by Pyrolysis-GC/MS/FPD Analysis

130

Antistatic PC

110
100
90
80

Antistatic PC

C4H9

C4H9

80

O P C4H9O P C 8 H 17

70

C4H9

C 8 H 1790

Relative Abundance%Transmittance

120

2

100

Reference PC

70
60

60

1

50
40
30
20
10

50

100

40
3000

2000

1500

1000

Wavenumbers (cm -1)
Figure 1 Infrared spectrum of an antistatic polycarbonate resin.
(Upper: Antistatic PC, Lower: Reference PC)

Relative Abundance

90

4000

2

Reference PC

80
70
60
50

3

40
30
20
10

2.2 Reactive Pyrolysis-GC/MS Analysis
It is difficult in general to detect or to identify components
derived from additives on pyrolysis-GC/MS analysis ofpolymeric materials, because a lot of thermal decomposition occurred from the matrix polymer masks small quantity of the components derived from the additives. On theother hand, additives in the polycondensation resins like
polycarbonates, polyesters and polyurethanes are
inclined to detect easily the component derived from theadditives on reactive pyrolysis-GC/MS with hydrolysis
reagents like methyl esterifying reagents. Since ester
bond or urethane bond in the matrix polymer are decomposed primarily by the reagents and the decompositions
derived from the matrix polymer are only monomer derivatives, it is easy to identify the component derived fromthe additives2)-5).
We tried the pyrolysis-GC/MS analysis on the antistatic
polycarbonate to identify the antistatic agent. Alkaline
methylation reagent (20% Tetramethylammonium hydroxide methanol solution (TMAH)) was added in a powderedsample pellet(around 0.1 mg) and the analysis conditionis shown in Table 1.
Table 1

Conditions of pyrolysis-GC/MS analysis.

Apparatus

Gas Chromatography-Mass spectrometry(GC/MS); JMS-Q1050GC of JEOL Ltd.
Pyrolyzer; PY-3030D of Frontier Laboratories
Ltd.

Pyrolysis
temperature

400℃

ColumnGC Temperature
Carrier Gas

UA- + 5 of Frontier Laboratories Ltd.
(Length: 30 m, Inner diameter: 0.25 mm,
Film thickness: 0.25 µm)
40℃（4 min）→ 10℃ /min → 320℃（Hold）
He, 1.0 ml/min. (Constant flow)

Total ion chromatogram(TIC) of pyrolysis-GC/MS analysis on the antistatic PC and the reference PC is shown
Figure 2.

0

5

10

15

20

25

30

35

40

Time (min)1：4-tert-Butylphenyl methyl ether；2：Bisphenol-A dimethyl ether；
3：Methyl phenyl ether
Figure 2 Reactive pyrolysis-GC/MS chromatogram of antistatic
polycarbonate resin.

Bisphenol-A dimethyl ether of a monomer derivativefrom polycarbonate, phenol and 4-tert-Butylphenyl methyl
ether of polymer end component were detected for bothof the antistatic polycarbonate and the reference polycarbonate.
With respect to the antistatic polycarbonate, Tri-butyl
phosphine oxide at 17.1 min. and phosphine compound
like Butyl diocthyl phosphine oxide at 24.3 min. weredetected but derivatives from the surface active agent likethe higher fatty acid salt generally used as an antistatic
agent was not detected.
According to the result, the phosphine compound, trialkyl phosphonium oxide, was presumed to be derived
from the antistatic agent, however it was not identified
whether the compound is a component of the agent or areaction product of the antistatic agent with TMAH.

ANALYSISWITH
WITHAA REACTIVE
REACTIVE PYROLY3.3. ANALYSISPYROLYSIS-GC/MS/FPD
SIS-GC/MS/FPD
3.1 Experiment
Trialkyl phosphine oxide was detected with a reactive
pyrolysis-GC/MS. In order to analyze whether it was theantistatic agent itself or the reaction product of the antistatic agent with TMAH, we tried to detect the agent witha pyrolysis GC/MS without TMAH called simple pyrolysisGC/MS, and since the agent contained phosphine, aFlame Photometric Detector (FPD), which detects phosphine and sulfur highly selectively and sensitively, was
combined to use with the pyrolysis GC/MS . This is asimultaneous analysis with pyrolysis-GC/MS/FPD 6)-9).
Eluted material from the GC is divided into MS detector
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Determination of Additives in Polymeric Material by Pyrolysis-GC/MS/FPD Analysis

100

MS(TIC)

Relative Abundance90
80

MS spectrum of peak-2

62
50

29

41

104

70
60

0

1

50

20

50

3

80

140

110

Relative Abundance

2

FPD(P)

70
60
50
40

C4 H9
P

62

C4 H9

29

41

104
131

20
10

0

3
8

10

12

14

16

18

20

22

24

26

28

20

50

80

110

30

Figure 3 Pyrolysis-GC/MS/FPD chromatograph of an antistatic
polycarbonate resin.

A peak at 13.6 min. of 4-tert-butylphenol based on an
end group of polycarbonate and another peak at 24.0
min. of bisphenol-A were detected in the MS chromatograph (TIC).
On the other hand, a strongly reported peak 2 at 14.6
min. in the FPD chromatogram was detected and identified a Tributyl phosphine according to MS spectrum analysis on a corresponding peak of TIC, as shown in Figure
4.

173
202

146

140

170

200

m/Z

Time (min)1：4-tert-Butylphenol； 4：Bisphenol-A

C4 H9

50

89

6

200

Tributyl phosphine

30

4

170

76

100

10
100

80

202

m/Z

30

90

131
146

2

40

173

89

4

20

Relative Absorbance

76

100

Relative Abundanceand FPD through the purged splitter installed at the endof the column and analyzed simultaneously.
3.2 Result and Discussion
Pyrolysis-GC/MS/FPD chromatogram of the antistatic
polycarbonate is shown in Figure 3.

Figure 4 Identification result of peak-2.

Peak 3 at 23.8 min. of FPD was identified Butyl-dioctyl
phosphine as the identification for the peak 2.
According to these results, we presumed that the antistatic agent in the polycarbonate was quaternary phosphonium salt, in detail tetraalkyl phosphonium salt,
shown in Figure 5.
Since the tributyl phosphineoxide detected by the reac-

C4 H9
R1

+

P

C4 H9

X－

C4 H9
R1：Alkyl group； X：Anion
Figure 5 Estimated structure of the antistatic agent.

tive pyrolysis-GC/MS analysis was not detected by thesimple pyrolysis-GC/MS analysis, we concluded that thetributyl phosphineoxide was occurred through a reactionof the quaternary phosphonium salt shown in Figure 5 ortributyl phosphine by pyrolysis of the phosphonium saltwith TMAH.
A structure of the fourth alkyl group in the estimatedstructure of Figure 5 was unknown. In order to determine
the structure, two kinds of tetra-alkyl phosphonium salt, tetrabutyl phosphonium (manufactured by Tokyo Chemical
Industry Co., Ltd.) and tributylmethyl phosphonium bis (trifluoromethanesulfonyl) imide (manufactured by Tokyo
Chemical Industry Co., Ltd.) were checked by the pyrolyFurukawa Review, No. 45

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Determination of Additives in Polymeric Material by Pyrolysis-GC/MS/FPD Analysis

sis-GC/MS/FPD analysis. The result is shown in Figure 6
and Figure 7.

Relative AbundanceRelative Absorbance

1
90
80
70
60
50
40
30
90
80
70
60
50
40
30

MS(TIC)1

FPD(P)

0

2

4

6

8

10

12

14

16

18

20

22

24

26

28

30

Time (min)76

Relative Abundance

100
80
60
40
29

20
0

41
40

60

80

100

P C4H 9
C4H 9

173

104

89
20

C4H 9

MS spectrum of peak-1

62

131
120

202

146

140

160

m/z

180

200

220

240

Relative Abundance Relative Absorbance Relative AbsorbanceFigure 6 Analytical result of the tetrabutylphosphonium bromide
with pyrolysis-GC/MS/FPD.

100
80
60
40
20
0

MS(TIC)

100
80
60
40
20
0

FPD(P)

6

8

76

100

0

1

10

29 41
50

12

14

16

18

20

Time (min)MS spectrum of peak-1

62

50

1

89 103 131 160
100

150

200

m/z

250

22

24

26

28

30

CH3
P C4 H9
C4 H9
300

350

400

Figure 7 Analytical result of the tributylmethlphosphoniumbis(trifluoromethanesulfonyl) imide with pyrolysis-GC/
MS/FPD.

QUANTATIVEANALYSISANALYSIS OF AN
4.4. QUANTATIVE
AN ANTIANTISTATICAGENT
AGENTWITH
WITH AA PYROLYSISPYROLYSIS GC/
STATIC
GC/MS/FPD
MS/FPD
It is known to detect phosphorus additives (Phosphorus
antistatic agent) highly selectively and sensitively by thesimultaneous analysis with pyrolysis-GC/MS/FPD and to
identify a structure of the additives. We further tried aquantitative analysis of the structure identified additives in
the polymer because it is important to know the content
of the additives from the product design and the quality
control perspective.
Since phosphorous compounds are detected highly
selectively and sensitively by the simultaneous PyrolysisGC/MS/FPD analysis, the quantitative analysis of the tetra-alkylphosphonium salt compound was tried.
4.1 Experiment
Tetrabutylphosphonium bromide was selected as a modelcompound and its methanol solution with a range of concentration were prepared. The different concentrated
methanol solution of 1 μL was obtained in a sample cup
and analyzed with the pyrolysis-GC/MS/FPD.
With respect to the quantitative evaluation, we made alinearity test for a calibration curve of peak area of tributyl
phosphine to sample mass between FPD and MS detector.
An area peak of MS chromatogram that is a fragment of
m/z=76 which is the highest intensity of MS spectrum isused for the calibration curve of the MS detector.
4.2 Result and Discussion
Figure 8 a) and b) show the calibration curve of the FPD
and the MS detector respectively. Correlation coefficient(R2) of the calibration curve for the FPD data was 0.9990
indicating a very good linearity. However, the correlation
coefficient for the MS detector calibration curve was
0.9984 and it was a worse linearity than FPD.
According to the result, we understood that FPD had an
advantage on the quantitative measurement for the tetrabutyl phosphonium salt compound.

We had only a peak at 15.2 min. of tributyl phosphine
for tetrabutylphosphonium bromide. On the other hand,
we did not detect any tributyl phosphine for tributylmethylphosphonium bis (trifluoromethanesulfonyl) imide but
detected at 11.1 min. methyl-dibutyl phosphine which
substituted one out of three alkyl group of tributyl phosfine in the methyl group.
In order to get a structure in which phosphine bondedwith three of alkyl group having same structure as tributyl
phosfine, four of alkyl group bonded with phosphine haveto be of the same structure. According to the above
results, we presumed that the antistatic agent in the antistatic polycarbonate was tetrabutylphosphonium salt
compound.
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Determination of Additives in Polymeric Material by Pyrolysis-GC/MS/FPD Analysis

100

30000090

Peak area

Relative Abundance

FPD

250000200000150000y = 108588x -4287.5
100000R² = 0.9990

MS(TIC)

80
70
60
50

1

40
30

4

20
10

5

3

100

50000

1

0
0.00

0.50

1.00

1.50

2.00

2.50

3.00

Amount(µg)a）FPD

Relative Absorbance

90

1000000
900000FPD(S)

80
70

2

60
50
40
30
20
10

MS

0

5

10

15

20

Time (min)Peak area

800000700000

25

30

35

40

1：Methyl mercaptan； 2：Dimethyl disulfide； 3：α-Methyl styrene；
4：Acetophenone； 5：α-Cumyl alcohol

600000500000Figure 9 Result of the thermal desorption-GC/MS/FPD analysis
for the vulcanized rubber.

y = 383551x -26773

400000R² = 0.9984

300000200000

0.00

0.50

1.00

1.50

2.00

2.50

3.00

Amount(µg)b）MS（m/z＝76）

Figure 8 Quantitative accuracy of the tetrabutylphosphonium
bromide by pyrolysis-GC/MS/FPD analysis.

ANALYSISOF
OFTHE
THE CURING
CURING AGENT
5.5. ANALYSISAGENT IN A
IN A VULCANIZEDRUBBER
VULCANIZEDRUBBER
5.1 Experiment
We investigated to identify a curing agent in a vulcanizedrubber by the pyrolysis-GC/MS/FPD analysis.
Analysis condition for the vulcanized rubber was thesame as the antistatic agent analysis except that the FPD
setting was changed to detect the sulfuric compound,and pyrolysis condition was also changed.
5.2 Result and Discussion
Figure 9 shows a result of the thermal desorption-GC/MS/FPD at 300℃ for the sample rubber. According to thedata for the MS detector, α-methyl styrene, acetophenone and α-cumyl alcohol were detected from 8 min. to
10 min. which were decomposed residue of dicumyl peroxide. This result would suggest the rubber to be vulcanized using peroxide.

However peak 1 at 0.9 min. and peak 2 at 2.3 min. weredetected and the MS spectrum corresponding to thesetwo peaks identified methyl mercaptan for peak 1 anddimethyl sulfide for peak 2.
Thermal residue of the rubber at 300℃ was pyrolyzed
at 600℃ and analyzed with pyrolysis GC/MS/FPD. The
result is shown in Figure 10 and sulfur dioxide at 1.1 min.
and another two of peaks near 9.6 min. were detected.
We analyzed the 9.6 min. peak in detail with the MS
spectrum and identified 2,5-cyclopenta[2,3-b]thiophenewith a molecular weight of 122.

Relative Absorbance Relative Abundance

0100

MS (TIC)

80
60
40
20
100

3

1

80

FPD(S)

60

2

40
20

2, 3
0

5

10

15

8

9
10
Time (min)

11

20

25

35

30

40

Time (min)Relative Abundance

100000

100
80

122

MS spectrum of peak-3

121

60
40
20
20

45 50
30

40

50

60

96

78

63

93
70

80

90

117

123

S
Molecular Weirht =122.2
Molecular Formula =C7H6S
2,5-Cyclopenta [2,3-b] thiophene

100 110 120 130 140 150 160 170 180 190 200

m/z

1：Sulfur dioxide； 2：2,4-Cyclopenta [2,3-b] thiophene；
3：2,5-Cyclopenta [2,3-b] thiophene
Figure 10 Result of the thermal desorption-GC/MS/FPD analysis
for the vulcanized rubber.

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Determination of Additives in Polymeric Material by Pyrolysis-GC/MS/FPD Analysis

It is reported that on pyrolyzing a sulfur vulcanized ethylene propylene diene rubber (EPDM) with ethylidene norbornene (ENB) as third component, the compound component is derived from crosslink of ENB with sulfur 10)-12).
According to the above result and C-S bonded material
detected on heating at 300℃, the rubber sample was presumed vulcanized with inorganic sulfur.
Since sulfur curing and peroxide curing are not used in
combination in general, the residue of the peroxide compound detected in Figure 9 was presumed a trace on
contacting other peroxide cured material.
In the case of analysis for cured rubber, the conventional analysis using only the MS detector does not identify
the decomposition corresponding to the sulfur cured rubber because of its masking by the decomposition of thematrix polymer. However analysis in combination with the
MS and the FPD detect a decomposition of sulfur cured
rubber easily, rapidly and accurately.

CONCLUSION
6.6. CONCLUSION
We succeeded to analyze phosphorus and sulfur additives in polymeric materials selectively and sensitively
with pyrolysis-GC/MS/FPD.
With the pyrolysis-GC/MS/FPD, with purged splitter
installed at the end of the column during analysis of additives in polymeric materials, we can enable the simultaneous detection through the MS and the FPD.
We can identify the structure of the compounds moreeasily than the conventional method and can make quantitative analysis highly selectively and more accurately.
Since phosphorus and sulfur additives are used not
only in the polymeric materials mentioned above but inmany product of coated materials on wire & cable, rubber
splicer and end splicer of power cable, and a regulationfor environmental loading will be tightened, we would liketo apply this analysis to material development, quality
control and solution for environmental regulation and also
to improve analysis technology.

REFERENCES
1) Kenji Iizuka: “Analysis of additives in polymeric materials by simultaneous measurement with pyrolysis-GC/MS/FPD” Summary ofSeventeenth Koubunnshi bunnseki touronnkai, Koubunnshi
bunnseki kennkyu konndannkai (2012) Ⅳ-05 (in Japanese)
2) Frontier Laboratories Ltd. “Analysis of Terminal Groups ofPolycarbonate (PC) by Reactive Pyrolysis” Technical note PYA2001E (2001)
3) Frontier Laboratories Ltd. “Analysis of Polyethylene Terephthalate(PET) by Reactive Pyrolysis” Technical note PYA2-006E (2002)
4) Frontier Laboratories Ltd. “Analysis of Additives in Polybutylene
Terephthalate (PBT)” Technical note PYA1-026E (2006)
5) Hajime Ohtani, Chuichi Wtanabe, Takayuki Masuda and Shin Tsuge“Structural Characterization of Terminal-modified and Branched
Polycarbonates by Pyrolysis-Gas Chromatography in the Presenceof Organic Alkali” BUNSEKI KAGAKU vol.60 (2011), 239 (inJapanese)6) Agilent Technologies “Identifying Pesticides with Full scan, SIM,
μECD and FPD from a Single Injection” Application note 59893299EN (2005)
7) Agilent Technologies “Screening of Hazardous Chemicals in
Homeland Security and Environmental Samples Using a GC/MS/
ECD/FPD with a 731 compound DRS Database” Application note
5989-4834EN(2006)
8) Agilent Technologies “Application for Capillary Flow Technology on
GC/MS analysis” Application note GCMS-200904NK-002 (2009) (inJapanese)9) Agilent Technologies “Organophosphorus Pesticides in Apple
Matrix by GC/MS/FPD using an Agilent J&W DB-35ms Ultra Inert
GC Column” Application note 5990-7165EN(2012)
10) Tadaoki Okumoto, Takao Yamada, Shin Tsuge and Hajime Ohtani,
Koubunshi Ronbunshu 54(1997),108 (in Japanese)11) Tadaoki Okumoto, Takao Yamada, Shin Tsuge and Hajime Ohtani,
Nihon Gomu Kyoukaishi 74(2001) 283 (in Japanese)
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