A novel needle trap device with single wall carbon nanotubes sol–gel sorbent packed for sampling and analysis of volatile organohalogen compounds in air

This paper describes a new approach that combines needle trap devices (NTDs) with a newly synthesized silanated nano material as sorbent for sampling and analysis of HVOCs in air. The sol–gel technique was used for preparation of the single wall carbon nanotube (SWCNT)/silica composite as sorbent, packed inside a 21-gauge NTD. Application of this method as an exhaustive sampler device was investigated under different laboratory conditions in this study. Predetermined concentrations of each analyte were prepared in a home-made standard chamber, and the effects of experimental parameters, such as temperature, humidity, sampling air flow rate, breakthrough volume and storage time on NTD, and the sorbent performance were investigated. The proposed NTD was used in two different modes and two different injection methods, and an NTD with a side hole, a narrow neck glass liner and syringe pump assisted injection of carrier gas were applied. The NTD packed with SWCNTs/silica composite was compared to the NTD packed with PDMS and also SPME with CAR/PDMS. For four compounds, LOD was 0.001–0.01 ng mL−1, LOQ was 0.007–0.03 ng mL−1, and the relative standard division for repeatability of method was 2.5–6.7%. The results show that the incorporation of NTD and SWCNTs/silica composite is a reliable and effective approach for the sampling and analysis of HVOCs in air. Coupling this system to GC–MS make it more sensitive and powerful technique.