کاربرد روش تله سوزنی (Needle Trap) در تعیین مقدار ترکیبات ارگانوهالوژن در هوا

  Background and aim s : The correct assessment of volatile organic compounds is a main stage of their control's action plan. Needle trap device (NTD) as a novel technique with all advantages of microextraction methods, is an inexpensive and rapid technique for survey of air pollution agents. In this study the performance of this technique was investigated for sampling and analysis of organohalogen compounds in the air.   Methods: The performance of NTD packed with PDMS for sampling and analysis of some of organohalogen compounds were investigated. The effects of performance parameters in three stages of sampling (BTV, temperature and RH), sampling storage (storage time) and analysis (desorption time and temperature) were investigated and compared with NIOSH proposed method and SPME with same sorbent.   Results: The NTD showed better performances in lower temperature and RH and the ability for storage of sampled analytes was more than 95% after 3 days. The optimum desorption temperature and time was 290◦C and 4 min respectively. The relative standard division for investigation of technique's repeatability for 5 NTD with same geometry was obtained 3.4-8.7%. In comparative study, the NTD showed better performances comparedto NIOSH proposed method and presented same performances compared to the SPME coated with similar coating fiber.   Conclusion: The NTD-PDMS revealed a good performance for sampling and analysis of volatile organohalogen compounds (HVOCs) in the air and we propose this method for air pollution monitoring of indoor and outdoor pollutants.