Dynamic and static removal of benzene from air based on task-specific ionic liquid coated on MWCNTs by sorbent tube-headspace solid-phase extraction procedure

Abstract

Human exposure to high levels of benzene in the air leads to toxic effects in human body and so, it is necessary to determine by high sensitivity and precision methodology. A simple and efficient method based on the triphenyl(3-sulfopropyl)phosphonium p-toluenesulfonate as TSIL was coated on multi-walled carbon nanotubes ([TPhPP][SUTO]–MWCNTs) and used for benzene vapor removal from air. By procedure, the tube and headspace sorbent based on solid-phase extraction coupled to gas chromatography-flame ionization detector (ST/HS-SPE-GC-FID) was used in dynamic and static systems, respectively. All effected factors including the flow rate, the mass sorbent, benzene concentration, the contact time and the temperature were optimized in dynamic and static systems. Chamber was designed for benzene generation in pure air, and then, mixture of gas moved to passive thermal desorption tubes (ST) or head space (HS) in the glass chromatography vials as dynamic and static methods, respectively. The benzene was eliminated from air with 10 mg of ([TPhPP][SUTO]–MWCNTs); C28H29O6PS2–MWCNTs, 1:1] at 25 °C, desorbed from the sorbent at 95 °C and measured by GC-FID. The removal efficiency and the absorption capacity of [TPhPP][SUTO]–MWCNTs for benzene were obtained to be 98.8% and 169.6 mg g−1 at flow rate of 300 ml min−1. The chemical adsorption of benzene from air was related to π–π, electrostatic, hydrophobic interactions between aromatic chains of TSILs with the benzene molecules, and it caused the increase the removal efficiently of benzene vapor from air more than 95%. The results were validated by GC–MS and spiking of real samples which was determined by GC-FID.