Fabrication and evaluation of a portable low-pressure headspace solid-phase microextraction device for on-site analysis

A compact, simple, and reliable low-pressure headspace solid-phase microextraction (LP-HS-SPME) device was fabricated, optimized, and successfully evaluated for on-site sampling of volatile and semivolatile environmental organic pollutants. The efficacy of low-pressure extraction for fast and accurate analysis of complex samples has been substantiated already, but the developed systems are laborious and usually use typical vacuum pumps which make them non-portable. Additionally, they are not suitable for direct sampling of analytes from solid samples. This LP-HS-SPME setup is pocket-sized and operator friendly and uses a syringe for the evacuation. It is very effective for the direct sampling of volatile and semivolatile analytes in complex liquid and solid matrices. A new electrospun nano-octadecylsilica/polyvinyl alcohol (NODS/PVA) coated fiber was prepared and characterized by SEM, EDX, and FT-IR techniques. The fiber was utilized with the developed device for the extraction and determination of PAHs in solid samples, by coupling with gas chromatography-flame ionization detection (GC-FID). A response surface methodology based on a central composite design was used to optimize the important experimental variables. The method calibration graphs were linear in the range of 0.01–1300 ng g⁻¹ and the detection limits were 3 to 50 pg g⁻¹. The repeatability for a single-fiber and inter-fiber reproducibility were obtained 5.3–9.9% and 12.2–18.5%, respectively. The NODS/PVA coated fiber and the LP-HS-SPME-GC-FID method were successfully assessed for the direct sampling and analysis of PAHs in polluted soil samples.