This document specifies a method for determination of volatile organic compounds (VOC) in indoor air and in air sampled for the determination of the emission from products or materials used in indoor environments (according to ISO 16000‑1) using test chambers and test cells. The method uses sorbent sampling tubes with subsequent thermal desorption (TD) and gas chromatographic (GC) analysis employing a capillary column and a mass spectrometric (MS) detector with or without an additional flame ionisation detector (FID)[13]. The method is applicable to the measurement of most GC-compatible vapour-phase organic compounds at concentrations ranging from micrograms per cubic metre to several milligrams per cubic metre. Many very volatile organic compounds (VVOC) and semi-volatile organic compounds (SVOC) can be analysed depending on the sorbents used.