**2.4 Sample analysis**

Desorption of both solvents from activated charcoal was achieved using carbon disulfide. In fact, after breaking the tube glass tips, the content was put in a glass flask already placed in an ice bath to avoid any vaporization. Then, the content was stirred for 30 min to promote desorption [19, 20].

After the separation of the organic phase using filtration, it was directly injected (1 μL) and analyzed by gas chromatography with flame ionization detector (GC-FID). The used instrument is a SHIMADZU® chromatograph GC-2014. The capillary

#### **Figure 3.**

*Location of dry cleaning facilities in a radius of 5 km from the city center of Sfax. The facilities that profited from indoor air monitoring are encircled in red.*

