Adsorption efficiency of functionalized multi-walled carbon nanotube in sampling trichloroethylene in air

Trichloroethylene (TCE) is an industrial solvent which is often used as a degreaser for metal parts. Due to adverse health effects and carcinogenic properties of this solvent, knowing its concentration in the workplace atmosphere is really crucial. Nowadays, carbon nanotubes with high efficiency are being used for sampling of this chemical.
Three types of static standard atmosphere with the concentrations of 18, 35, and 53 ppm were produced. Then, sampling tubes which contained 10 mg of functionalized multi-walled carbon nanotubes were prepared. Subsequently, air standard atmosphere was made inside sampling bags. The mean adsorption efficiency was examined in three sampling flows (0.1, 0.15, and 0.2 L/minute). Finally, desorption was performed by carbon disulfide and analysis was conducted using gas chromatography coupled to mass spectrometry) GC/MS (according to the instructions of NIOSH 1022 and OSHA 1001.
The highest amount of adsorption occurred in the flow of 0.1 L/minute (81.51±3.72). Furthermore, considering the three studied concentrations of trichloroethylene (18, 35, and 53 ppm); the highest efficiency was recorded at 18 ppm concentration (83.18±11.67). The highest adsorption efficiency with the lowest standard deviation (80.55±3.85) was observed in samples that were immediately injected into the GC/MS machine.
Given that time-lapse had no significant effect on adsorption efficiency, it is argued that the pollutant had suitable stability on the surface of the adsorbent. The results of this study show that multi-walled carbon nanotubes have better performance at lower concentrations of trichloroethylene.