A Needle Trap Device Packed with Nanoporous Silica Sorbents for Separation and Gas Chromatographic Determination of Polycyclic Aromatic Hydrocarbons in Contaminated Soils

Abstract

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%.

Advanced Solid-Phase Microextraction Techniques and Related Automation: A Review of Commercially Available Technologies

“…In the NTME technique, commercial sorbents such as PDMS-DVB, Carboxen, Carbopack X, Tenax TA, and polymer-based beads are used to sample organic compounds from different media. Recently, Mieth et al [87] showed that a combination of different sorbents into the same needle trap could enhance the extraction performance, while Maleki et al [88] customized the NTME with nanoporous silica sorbents, showing the possible wide range of applications for this technique.…”

A thin‐layer solid‐phase extraction–liquid film elution technique used for the enrichment of polycyclic aromatic hydrocarbons in water

“…For fine particle-based methods, various types of containers have been proposed for the microcolumn such as a pipette tip [29], nozzle of a disposable syringe [30], syringe [31], and 21-gauge stainless steel needle [32]. In microcolumn techniques, repeated aspirating/dispensing cycles of the sample solution and eluent are necessary to attain adsorption or desorption equilibria.…”