On-line measurements of products of the ozonolysis of isoprene by PTR-MS and NI-CIMS were carried out using a pillow-shaped bag made of a copolymer of hexafluoropropylene and tetrafluoroethylene (FEP; bag volume 1 m3; 1800 1570 mm; thickness of the FEP sheet: 50 mm, GL Sciences, Tokyo, Japan). The experimental setup was similar to that used by Sakamoto et al. (2013). Ozone was produced by irradiation of air with vacuum ultraviolet light from a low-pressure mercury lamp during the introduction of air into a bag. Then, a cylinder gas of isoprene/N2 was introduced into the bag. The initial mixing ratios of isoprene and ozone were fixed at approximately 2 ppmv and 4 ppmv, respectively. The experiments
were carried out under dry conditions and without seed particles.