Hydrocarbons from samples of traffic-polluted urban air were separated by gas chromatography on an aluminium oxide column and assessed simultaneously by photoionization detection (PID) and flame ionization detection (FID) after effluent splitting. The 10.2 eV photoionization detector selectively detects alkadienes and alkenes but not alkanes and alkynes in the C3-C5 region. The maximum PID/FID response ratio for alkadienes and alkenes is also obtained in this region. The analytical system as a whole is particularly favourable for the C3-C5 alkenes. Analytical data are given for propadiene, 1,3-butadiene, propene, butenes and pentenes.
Air Pollutants Alkadienes