## 3 Results
### Extracted Ion Data for Carpet Substrates
#### 3.2.3 Extracted Ion Data for Carpet #3 Berber 100% Dyed Polyester Carpet  
The third studied carpet was Berber 100% Dyed Polyester carpet. The TIC and extracted ion profiles for this carpet burned in the absence and presence of ILs is presented in Figure 10. The identified compounds in carpet #3 were benzene (RT = 1.81 min, RSI = 938), phenol (RT = 2.98 min, RSI = 969), toluene (RT = 3.17 min, RSI = 956), 2,4-dimethy-1-heptene (RT = 4.89 min, RSI = 947), ethylbenzene (RT = 5.45 min, RSI = 932), and styrene (RT = 6.30 min, RSI = 948).  
Figure 9: Extracted indane profiles of (**a**) carpet #2, burned without ILs; (**b**) carpet #2 burned with gasoline; and (**c**) neat gasoline.  
Potential Interference with the Identification of Gasoline  
Although toluene and ethyl benzene, target compounds of gasoline, were identified in carpet #3 burned without ILs, a comparison of extracted ion profiles in carpet #3 burned without ILs with that of neat gasoline shows that the profiles are distinguishable based on the number of identified compounds and the relative abundance. The profiles obtained from carpet #3 burned with gasoline clearly demonstrate the characteristic alkylbenzene, polyaromatics, and indane profiles of gasoline. The extracted alkylbenzene profiles are compared in Figure 11 as an example. It should be noted that the relative peak abundance for toluene (RT = 3.17 min, RSI = 956) is much higher compared to the other characteristic alkylbenzenes since, it is also a pyrolysis product of polyester carpet.  
Figure 11: _Cont._  
Figure 10: Total ion chromatograms (_m_/_z_ 50–500) of carpet #3 (**a**) burned without ILs; (**b**) burned with gasoline; (**c**) burned with kerosene.  
Comparison of the extracted indane profiles of carpet #3 burned with and without gasoline with the indane profile of neat gasoline, shows that the indane profile can be reliably used to confirm the presence of gasoline. The indane profile of carpet #3 burned without gasoline does not match with that of neat gasoline, whereas the indane profile of carpet #3 burned with gasoline matches with that of neat gasoline (Figure 12).  
Figure 11: Extracted aromatic (alkylbenzenes) profiles of (**a**) carpet #3 burned without ILs; (**b**) carpet#1 burned with gasoline; and (**c**) neat gasoline.  
Potential Interference with Identification of Kerosene  
Comparison of the profiles obtained for carpet #3 burned without kerosene and those of unburned neat kerosene does not show interferences. On the other hand, the TIC and extracted ion profiles obtained from carpet #3 burned with kerosene, present the characteristic alkane, and cycloalkane profiles of kerosene. The obtained results clearly demonstrate that the tested SPME method can be reliably used to distinguish between carpet burned without ILs and carpet burned with kerosene.  
The extracted alkane profiles of carpet burned without ILs is compared to those of carpet burned with kerosene and neat kerosene, for example in Figure 13.  
Figure 12: Extracted indane profiles of (**a**) carpet #3 burned without ILs; (**b**) carpet #3 burned with gasoline; and (**c**) neat gasoline.  
Figure 13: Extracted alkane profiles of (**a**) carpet #3 burned without ILs; (**b**) carpet #3 burned with kerosene; and (**c**) neat kerosene.