Authors' response to reviewer's comments

Abstract

We would like to thank the referee for his/her careful reading of the manuscript and the detailed comments that were provided. We think we addressed all the referee's concerns and we edited our manuscript when further details or clarifications were needed. 1) Collection system and experimental setup. The collection system poses some serious problems. Positive artefacts are well known on quartz filters. Some of the filters were highly charged (PF1, PF2, PF3). We could expect that C1 AMTD Interactive comment Printer-friendly version Discussion paper a kind of "soot cake" is formed on the front filters increasing the filtration efficiency and causing more adsorption of the gaseous compounds onto the deposited particles (see Fig. 1 images front filters).