Volatile organic compounds emitted by the stacks of restaurants

Volatile organic compound (VOC) samples were collected from the exhaust stacks on the roofs of a university canteen, a charcoal-grilled chicken restaurant and a woodoven roasted piglet restaurant on sorbent tubes with Carbopack B and C packing and analysed by thermal desorption-gas chromatography-flame ionisation detection. Concurrent sampling of carbonyls was also conducted using 2,4-dinitrophenylhydrazine cartridges with analysis by highperformance liquid chromatography. Two main reasons may have contributed to the emission of much lower levels in the exhaust of the kitchen of the university canteen: (i) hoods having thick filters and (ii) use of gas and electricity as energy sources for cooking. Larger emission rates of 2-butanone were measured from boiled dishes prepared in the canteen than those from other menus. Chlorinated VOCs have only been detected in samples of the chicken restaurant. Benzene was the compound with the highest emission rates from the chicken and piglet restaurants (201 and 178 kg year−1, respectively). In general, the emissions from most dishes presented a higher concentration of acetaldehyde compared to formaldehyde. The ozone formation potentials of VOCs and carbonyls emitted by the two restaurants are incomparably higher than those estimated for the university canteen. The reactivity of VOCs from the chicken and piglet restaurants is higher than those reported for vehicle emissions or other sources