فهرست نشریات علمی دسترسی آزاد ایران

In this study, the synthesis method of silica aerogel adsorbent was modified, magnetized, and packed into a needle trap device, and it was employed as a novel method for the sampling and analysis of benzene, toluene, ethyl benzene, and xylenes (BTEX) in air. The adsorbent was characterized using X-ray diffraction analysis (XRD), Fourier-transform infrared spectroscopy (FT-IR), and field-emission scanning electron microscopy. Gas Chromatography (GC) was used for the analysis of the analytes of interest. The sampling and analysis conditions were optimized in the laboratory. The optimal conditions, including instrumental parameters (desorption temperature and time) and environmental factors (ambient temperature and humidity), were determined for the application of the proposed needle trap device in the identification of BTEX compounds. The optimized method showed that the best desorption time for BTEX analytes was 2 min, and desorption temperatures of 250-260°C were determined as optimal conditions for BTEX compounds. Sampling is most effective at 24°C with 30% relative humidity. Limit of detection of 0.03–0.06 ng/mL, limit of quantification of 0.10–0.18 ng/mL, and method repeatability with a relative standard deviation of 3.6%–14.6% were obtained for the proposed method. The study showed that the modified silica aerogel in the needle trap method is highly efficient for sampling and monitoring BTEX compounds in workplace air. Compared to traditional methods, it offers easier implementation, portability, and less need for complex equipment, enabling fast and cost-effective BTEX monitoring in occupational settings.