Validation of a New Method for the Monitoring of Environmental Benzene at Low Concentration Using the Needle Trap Device

Benzene has been emitted from most industrial chemicals and automobile gasoline, environmental and occupational exposure to a wide range of benzene has been observed. The needle trap device is a novel and inprogress exhaustive extraction trap which fluid can pass through it by pump. In this study, NTD consisted of a needle gauge 21 with 10 cm length that’s packed with Carboxen-1000 for adsorbing benzene. Samples were analyzed by gas chromatography coupled with flame ionization detector and peak verification was examined by gas chromatographymass spectrometry. Linear range concentration was 25-2500 ppb and limit of detection; limit of quantitation and bias were 10, 20 ppb and -0.12 respectively. The agreement of atmospheric standards analyzed by the method of this study and OSHA’s method was examined by the Bland-Altman plot. According to this method, the agreement of two sets of data was established. 20 samples were taken to check the applicability of the developed method in a refinery unit. Benzene concentrations were measured in the range of 0.15 to 1.2 ppm. The results showed that needle trap device carboxen-1000 is a reliable and effective approach and more sensitive and powerful technique for the sampling and analysis of low concentration of benzene in the atmosphere.