The VOCs were intermediately trapped at 50 C and analyzed on the basis of gas chromatography with mass spectrometric detection. The selected compounds were identified and quantified on the basis of total ion current recordings. The column used was a DB-5MS capillary column and the following GC-oven program was run: 0 C (3 min), then 10 C/min to 320 C (5 min). The internal standard dodecane was solely used to demonstrate complete desorption of the VOCs from Tenax tubes. The peak areas of the selected compounds were not corrected with the internal standard.Quantification was conducted on the basis of the results obtained upon GC–MS analysis of air in a Tedlar bag filled with a known amount of air and spiked with known amounts of the reference substances (i.e., formaldehyde, acetaldehyde, benzene, naphthalene,toluene, styrene, o/m/p-xylene; Sigma–Aldrich) with a purity of P99%. The reference substances were brought into the Tedlar bag by injecting solutions of the substances. Subsequently, the air in the Tedlar bag was sampled with the same procedure as the sampling procedure for Hazleton chambers.