Diffusive sampling of airborne furfural by solid-phase microextraction device with on-fiber derivatization

The solid-phase microextraction (SPME) device was used as a diffusive sampler for airborne furfural. The polydimethylsiloxane/divinylbenzene (PDMS/DVB) fiber was used, and O-2,3,4,5,6-(pentafluorobenzyl)hydroxylamine hydrochloride (PFBHA) was first loaded onto the fiber. The SPME fiber assembly was then inserted into a PTFE tubing as a diffusive sampler. Known concentrations of furfural around the threshold limit values (TLVs)/time-weighted average and specific relative humidities (RHs) were generated by syringe pumps in a dynamic generation system. Validations of the SPME diffusive sampling with the US Occupational Safety and Health Administration (OSHA) organic method 72 were performed side-by-side in an exposure chamber at 25 °C. Gas chromatography/mass spectrometry (GC/MS) was used for sample analysis. The experimental sampling constant of the sampler was found to be (1.75 ± 0.03) × 10−2 (cm3 min−1) at 25 °C, whereas face velocity (0–0.25 m s−1) as well as RHs (10–80%) were proven to have no effects on the sampler. The correlations between the results from both SPME device and OSHA organic method 72 were found to be linear (r = 0.9849) and consistent (slope = 0.99 ± 0.03). However, the variations of diffusion coefficients at different temperatures needs to be considered, and the adjustment of sampling constant was a must when sampling at temperatures different from 25 °C.