Inhibiting sorbent stripping by designing a sorbent‐packed porous probe for headspace solid‐phase microextraction

Abstract

To prevent the stripping of coating sorbents in headspace solid-phase microextraction, a porous extraction probe with packed sorbent was introduced by using a porous stainless steel needle tube and homemade sol-gel sorbents. The traditional stainless-steel needle tube was punched by a laser to obtain two rows of holes, which supply a passageway for analyte vapor during extraction and desorption. The sorbent was prepared by a traditional sol-gel method with both poly(ethylene glycol) and hydroxy-terminated silicone oil as coating ingredients. Eight polycyclic aromatic hydrocarbons and six benzene series compounds were used as illustrative semi-volatile and volatile organic compounds in sequence to verify the extraction performance of this porous headspace solid-phase microextraction probe. It was found that the analysis method combining a headspace solid-phase microextraction probe and gas chromatography with mass spectrometry yielded determination coefficients of no less than 0.985 and relative standard deviations of 4.3-12.4%. The porous headspace solid-phase microextraction probe showed no decrease of extraction ability after 200 uses. These results demonstrate that the packed extraction probe with porous structure can be used for headspace solid-phase microextraction. This novel design may overcome both the stripping and breakage problems of the conventional coating fiber.