Fast field sampling/sample preparation and quantification of volatile organic compounds in indoor air by solid-phase microextraction and portable gaschromatography

Solid-phase microextraction (SPME) was used as a rapid, simple, convenient, and cost-effective technique to sample volatile organic compounds (VOCs) i n indoor air. Concentrations of five target VOCs, including benzene, toluen e, ethylbenzene, m,p-xylenes, and hexane, were determined on site in severa l buildings around the city of Waterloo, Canada. Samples were collected wit h a polydimethylsiloxane/divinylbenzene (PDMS/DVB) porous polymer-coated fi ber and 1-min sampling time, followed by 15-min analysis. Fast separation a nd speciation of common indoor air pollutants was possible with the use of a modified, SRI portable gas-chromatography (GC) instrument, equipped with a photoionization (PID), a flame ionization (FID), and a dry electrolytic c onductivity detector (DELCD) in series. The mass calibration for target VOC s was based on the diffusion-controlled extraction onto the adsorptive SPME coating. The method detection limits for the target VOCs in air were betwe en one and nine parts per billion (ppb). Target VOC concentrations measured with SPME/fast GC were comparable to those obtained with the National Inst itute of Occupational Safety and Health (NIOSH) 1501 method. The use of SPM E coupled to a portable GC instrument allowed for at least a tenfold reduct ion of the total sampling and analysis time. The short SPME sampling time c ombined with fast, portable GC provided a near-real-time measurement of tar get VOCs. The results suggest that fast air sampling with adsorptive SPME f ibers can be used for analyte speciation based on diffusion coefficients. T he combination of SPME and a portable fast GC proved to be a very premising technique for conducting cost-effective indoor air quality surveys and mak ing on-site decisions to control VOC emissions. (C) 2000 John Wiley & Sons, Inc.