Supplementary material to "Measurement report: Characteristics and sources of non-methane VOCs and their roles in SOA formation during autumn in a central Chinese city"

Abstract

dichlorobenzene (MW 147.00). The zero air and diluted standard gas (with 10 ppbv) are measured for several cycles, respectively. Based on the PTR-MS Viewer 3 software, the transmission features of the above masses are calculated, thereby a transmission curve can be made. Accordingly, the transmission values of the species which are not mentioned above can be estimated to calculate the concentrations (Taipale et al., 2008). Text S2. PMF analysis results of OA from ACSM Positive matrix factorization (PMF) analysis is performed for 2 factors in order to figure out the secondary component in OA, and the solution with Fpeak=0 is chosen as the optimal results. Finally, the total OA in Beijing was resolved into a hydrocarbonlike OA (HOA) factor and oxygenated OA (OOA) factor, and the relevant mass spectra, time series, diurnal variations, proportion, and correlations with external tracers of the OA factors are displayed in Fig. S1 and S2. Text S3. Input VOC data for PMF model According to the user's guide, PMF is a multivariate factor analysis tool that decomposes a matrix of speciated sample data into two matrices: factor contributions (G) and factor profiles (F). As a receptor model, the goal of this model is to solve the chemical mass balance (CMB) between measured species concentrations and source profiles, and the equation can be shown as follows: