*2.4. HS-SPME–GC–MS Analysis*

Head space-solid phase micro extraction–gas chromatography–mass spectrometry (HS-SPME–GC–MS) analysis results are shown in Table 2. GC-MS chromatograms, for raw and treated samples (the sample with the lowest TOC after the process was selected), are shown in Figures S1 and S2.

The identified compounds were mainly cosmetic bases (e.g., decamethyltetrasiloxane or decamethylcyclopentasiloxane) and fragrances (e.g., 1,3,4,6,7,8-hexahydro-4,6,6, 7,8,8-hexamethyl-cyclopenta(*g*)-2-benzopyran (galaxolide) or 4-isopropenyl-1-methyl-1 cyclohexene (limonene)).

All compounds detected with HS-SPME-GC-MS were removed during the treatment process. No new compound was detected during the process. HS-SPME-GC-MS is a useful tool that can be used to confirm the high efficiency of the treatment process.


**Table 2.** Raw wastewater head space-solid phase micro extraction–gas chromatography–mass spectrometry (HS-SPME–GC– MS) analysis results.
