Measurement of total volatile organic compound (TVOC) in indoor air using passive solvent extraction method

The measurement of total volatile organic compound (TVOC) is effective for evaluating indoor air quality. This study aimed to develop a procedure for TVOC measurement using a passive solvent extraction method (SD_passive). The quantitative and qualitative performances of SD_passive for TVOC measurement were compared to those of the active thermal desorption method (TD_active). TVOC concentrations of the SD_passive method were highly correlated with those of the TD_active method. However, below 600g/m(3), they were slightly underestimated compared to those of the TD_active method. This was because the sampling rates (SRs) of specific volatile organic compounds (VOCs), such as cyclic siloxane and nonanal, which are often detected in indoor air, were lower than those of toluene used for calculating TVOC concentration in the SD_passive method. Therefore, several correction methods using the appropriate SR were explored to obtain TVOC concentrations equivalent to those obtained using the TD_active method. In the proposed method, individual SRs were used for specific VOCs and estimated SRs were used for other VOCs as a function of the total ion chromatogram retention time (Rt) (SR=96, Rt<25; SR=-3.2, Rt+150, Rt25). Consequently, below 600g/m(3), the SD_passive method could achieve a qualitative performance equivalent to that of the TD_active method. The ten major compounds of TVOC identified using the SD_passive method agreed with those using the TD_active method. Overall, the proposed method is easy to implement, inexpensive, and suitable for rapid evaluation of indoor air quality.