NMHC measurements of motorway emissions during the BAB II field campaign

Non-methane hydrocarbons (NMHC) were measured vertically resolved up-wind and down-wind of the motorway BAB A656 Heidelberg–Mannheim, Germany, for 4 weeks in April and May 2001. The horizontal distribution of C2–C9 aliphatic and aromatic hydrocarbons was monitored by using two compact quasi on-line gas chromatography (GC) instruments. The vertical distribution of NMHC was determined by using adsorption tubes, which were analysed off-line by GC in the laboratory. More than 50 NMHC were detected and 26 of them were quantified. From the measured data, the emission source strength for a variety of NMHC were calculated and discussed.