A novel needle trap device with single wall carbon nanotubes sol–gel sorbent packed for sampling and analysis of volatile organohalogen compounds in air Mahmoud Heidari a , Abdolrahman Bahrami a,n , Ali Reza Ghiasvand b , Farshid Ghorbani Shahna a , Ali Reza Soltanian c a Department of Occupational Health, School of Public Health, Hamadan University of Medical Sciences, Hamadan, Iran b Department of Analytical Chemistry, Faculty of Science, Lorestan University, Khoramabad, Iran c Department of Biostatistics and Epidemiology, School of Public Health, Hamadan University of Medical Sciences, Hamadan, Iran article info Article history: Received 30 April 2012 Received in revised form 16 September 2012 Accepted 17 September 2012 Available online 25 September 2012 Keywords: Needle trap device (NTD) Carbon nanotube Sol–gel technique Volatile organohalogen compounds (HVOCs) abstract 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. & 2012 Elsevier B.V. All rights reserved. 1. Introduction Halogenated volatile organic compounds (HVOCs) are also known as volatile organohalogen compounds. According to European VOC solvent directive 1999/13/EC, organohalogen compounds are those which have at least one halogen (fluorine, chlorine, bromine, iodine) atom with vapor pressure of more than 10 Pa at 20 1C [1]. These are very significant environmental and occupational pollutants due to their widespread usage and high toxicity. HVOCs are widely used in industry as solvents, cleaning and degreasing agents, polymerization and blowing agents, and also as disinfecting agents. Because of high vapor pressure, these compounds can easily be released into the workplace, and workers health may be affected [2–5]. Most VOCs, particularly the halogenated hydrocarbon solvents, are known to be hazardous. HVOCs can enter the human body by inhalation, dermal contact or inadvertent ingestion via hand-to-mouth contact. These chemicals can then enter the bloodstream and may either be excreted or accumulate in different organs. Industrial indoor exposure to these solvents may cause cancer or mutagenic, or teratogenic effects and thus represents a direct health risk to workers [6]. Sampling and analysis of HVOCs are very important for accurate assessment of indoor and outdoor exposure. The U.S. Environment Protection Agency (EPA) has recommended method 8010B, and the U.S. National Institute of Occupational Health and Safety (NIOSH) offers method 1003 for the sampling and analysis of halogenated volatile hydrocarbons in water and air matrices. There are also some techniques for sample preparation, preconcentration, and separation of HVOCs. The most common technique for analyzing HVOCs in water is liquid–liquid extraction with an organic solvent (hexane or pentane) and a subsequent analysis of the extract via gas chroma- tography with electron-capture detection (LLE–GC–ECD) [7,8]. The LLE–GC–ECD technique has many qualitative and quantitative limitations, and it is not recommended for sampling and analysis of air. There are also some microextraction techniques for pre- paration, preconcentration, and analysis of HVOC samples, such as liquid phase microextraction (LPME) techniques. However, these techniques are not suitable for analysis of HVOCs found in air. The other techniques are the gas phase extraction technique and the direct aqueous injection technique (pure water samples), which are suitable for HVOCs. Solvent microextraction (SME), solid phase Contents lists available at SciVerse ScienceDirect journal homepage: www.elsevier.com/locate/talanta Talanta 0039-9140/$ - see front matter & 2012 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.talanta.2012.09.032 n Corresponding author. Tel.: þ98 91 8812 4675; fax: þ98 81 1838 0509. E-mail address: bahrami@umsha.ac.ir (A. Bahrami). Talanta 101 (2012) 314–321