A needle trap device packed with a sol–gel derived,multi-walled carbon nanotubes/silica composite for sampling and analysis of volatile organohalogen compounds in air

A needle trap device (NTD) packed with silica composite of multi-walled carbon nanotubes (MWCNTs) prepared based on sol–gel technique was utilized for sampling and analysis of volatile organohalogen compounds (HVOCs) in air. The performance of the NTD packed with MWCNTs/silica composite as sorbent was examined in a variety of sampling conditions and was compared with NTDs packed with PDMS as well as SPME with Carboxen/PDMS-coated fibers. The limit of detection of NTDs for the GC/MS detection system was 0.01–0.05 ng mL⁻¹ and the limit of quantitation was 0.04–0.18 ng mL⁻¹. The RSD were 1.1–7.8% for intra-NTD comparison intended for repeatability of technique. The NTD-MWCNTs/silica composite showed better analytical performances compared to the NTD-PDMS composite and had the same analytical performances when compared to the SPME-Carboxen/PDMS fibers. The results show that NTD-MWCNTs-GC/MS is a powerful technique for active sampling of occupational/environmental pollutants in air.