VOCs Measurements in Residential Buildings: Quantification via Thermal Desorption and Assessment of Indoor Concentrations in a Case-Study

Volatile organic compounds (VOCs) represent one of the most important categories of pollutants, influencing the air quality and human health and well-being in indoor environments. In the present study, 12 selected VOCs were sampled using Tenax TA tubes and analyzed by thermal desorption combined with gas chromatography and a flame ionization detector (TD-GC-FID). The TD-GC-FID method was optimized to obtain the separation of all the analytical peaks (including m- and p-xylene) and a satisfactory sensitivity, with low detection (between 0.14 and 0.31 ng) and quantification (between 0.47 and 1.02 ng) limits. The whole procedure was firstly assessed with the analysis of four co-located tubes exposed at an outdoor monitoring site, with results that revealed a very low inter-tubes variability (relative standard deviations of parallel measurements <5%). Then, the measurement protocol was used to quantify the indoor concentrations of the target VOCs in nine different homes during the dishwasher washing cycle. The most abundant detected VOC in all dwellings was d-limonene (mean: 231 µg/m3; maximum: 611 µg/m3). All the other compounds were monitored at concentration levels one or two orders of magnitude lower than d-limonene, and were generally comparable with those found in the scientific literature. In terms of health concerns, the measured concentrations were always well below the safe levels established for the protection of the general population in living environments