Solid-phase microextraction-based midget on-site emission cell method extended to low volatility semi-volatile organic compounds for the measurement of gas-phase concentration at the material surface

On-site semi-volatile organic compound (SVOC) source identification and gas-phase concentration at the material surface (y 0 ) measurements are needed to model indoor exposure to harmful chemical additives emitted by building and furniture materials. The solid-phase microextraction (SPME)-based midget on-site emission cell (MOSEC) method is a passive device developed to address these needs. However, converting the sampled SVOC amount into the gas-phase concentration in the MOSEC is the critical step because an atmosphere with a known SVOC gas-phase concentration is required to calibrate the method. In this work, an experimental setup was designed to generate atmospheres containing SVOCs. These atmospheres were transferred to a MOSEC. By design, the MOSEC could be isolated to perform passive SPME sampling. The analyte concentration was monitored by active sampling on sorbent tubes as a reference method. Calibration was then performed following Fick's first law of diffusion under steady state conditions: several SPME samplings of different exposure times were carried out in the MOSEC. The method was applied to the measurement of y 0 of tris(2-chloroisopropyl) phosphate (TCPP), triphenyl phosphate (TPP), 2-ethylhexyl diphenyl phosphate (EHDPP) and 1,2-cyclohexane-dicarboxylic acid, dinonyl ester (DINCH), emitted by a polyurethane (PU) foam and a polyvinyl chloride (PVC) furniture covering. The performance parameters of this method were also evaluated. The results agreed with y 0 values previously reported and were close to y 0 values obtained using vapor pressure-based empirical relationships proposed in the literature. This work provides a simple method to calibrate SPME passive sampling methods for low to very low volatility SVOCs in air. • Generation of the air containing low volatility SVOCs: TPP, EHDDP and DINCH. • Calibration of SPME-based MOSEC method via reference active sampling. • Application to y 0 measurements of four SVOCs emitted by furniture materials. • Consistency with previously reported y 0 and V P -based correlations.