Extended Data Fig. 2: Wall-loss rates of oxidation products measured by (a) NO3-CIMS and (b) PTR3.
From: Anthropogenic organic aerosol in Europe produced mainly through second-generation oxidation
The NO3-CIMS detects mostly HOMs (LVOCs and ELVOCs) which are irreversibly lost to the wall while the PTR3 detects mostly SVOCs which are not or with a low sticking coefficient lost to the wall. For sulfuric acid (98 Da) a wall loss rate of 0.002 s−1 was measured. Assuming an average molecular mass of 200 Da for HOMs and considering a mass1/2 dependence for the diffusivity, the average wall loss rate for HOMs is expected to be around 0.0014 s−1, shown as a red line in the figures. This rate is in good agreement with the wall loss rates of HOMs measured with the NO3-CIMS (0.00146 s−1, with a 10th percentile of 0.00099 s−1 and a 90th percentile of 0.00197 s−1).
