SBA-15 and MCM-41 nanoporous silica sorbents were synthesized and functionalized by amine groups and used, for the first time, for packing a needle trap device (NTD). The characteristics of the synthesized SBA-15 and MCM-41 sorbents were investigated by X-ray diffraction, scanning electron microscopy and Fourier transfer infrared spectroscopy. The NTD coupling to gas chromatography with a flame ionization detector (GC-FID) was carried out to extract and determine polycyclic aromatic hydrocarbons (PAHs) in contaminated soil samples. The performances of the sorbents for the extraction of PAHs were compared under identical conditions and the NH2-SBA-15 sorbent showed superior results. Extraction temperature, extraction time, recycling gas flow rate, sample moisture, desorption time and desorption temperature were evaluated and optimized for the system. Under the optimum conditions, detection limits of 0.0004-0.0035 μg g-1, quantitation limits of 0.001-0.01 μg g-1 and relative standard deviations of 7.4-14.9% were obtained for the PAHs. The results showed the more effectiveness of this sorbent for the extraction of the PAHs compared to that of a commercial sorbent. The method was successfully applied for the extraction and determination of PAHs in polluted soil samples collected from gas stations, with recoveries ranging from 64 to 112%.
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http://dx.doi.org/10.1093/chromsci/bmy056 | DOI Listing |
Discov Nano
November 2024
School of Electronic and Electrical Engineering, Hongik University, Seoul, 04066, Republic of Korea.
Anal Chim Acta
November 2024
Department of Chemistry, University of Waterloo, Waterloo, ON, N2L 3G1, Canada. Electronic address:
In time-weighted averaging (TWA) with needle trap extraction (NTE), the control of the sampling rate is critical for accurate analysis. By adjusting the diffusion length and cross-sectional area, the sampling rate can be modified in accordance with Fick's first law of diffusion. In this study, deactivated fused silica tubing (DFST) of varying lengths was used to fine-tune these parameters, allowing for precise control of the sampling rate in TWA-NTE devices.
View Article and Find Full Text PDFFront Oncol
October 2024
Department of Pathology, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou, China.
Background: Myoepithelial carcinoma (MECA) is a malignant tumor primarily affecting the salivary gland, most frequently in the parotid gland. It can manifest as primary or secondary to pleomorphic adenoma or benign myoepithelioma. MECA exhibits aggressive behaviors.
View Article and Find Full Text PDFJ Chromatogr A
November 2024
Department of Biostatistics, School of Public Health and Research Center for Health Sciences, Hamadan University of Medical Sciences, Hamadan, Iran.
Ecotoxicol Environ Saf
September 2024
Institute of Clinical Physiology (IFC-CNR), National Research Council, Pisa, Italy. Electronic address:
Microplastics (MPs) are recognized as a major environmental problem due to their ubiquitous presence in ecosystems and bioaccumulation in food chains. Not only humans are continuously exposed to these pollutants through ingestion and inhalation, but recent findings suggest they may trigger vascular inflammation and potentially worsen the clinical conditions of cardiovascular patients. Here we combine headspace analysis by needle trap microextraction-gas chromatography-mass spectrometry (HS-NTME-GC-MS) and biological assays to evaluate the effects of polystyrene, high- and low-density polyethylene MPs on phenotype, metabolic activity, and pro-inflammatory status of Vascular Smooth Muscle Cells (VSMCs) the most prominent cells in vascular walls.
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