Measurement Procedures of Polycyclic Aromatic Hydrocarbons in Undiluted Diesel Exhaust Gases

Procedures for the measurement of aromatic hydrocarbons in undiluted Diesel exhaust gases were developed and compared. In the first one, hydrocarbons are trapped on sorbents, then analysed by thermal desorption coupled to GC/FID. Eight monoaromatic hydrocarbons and eleven PAHs from two to four aromatic rings have been detected. The second procedure uses three media: a filter, a condenser and a resin cartridge. After extraction, samples are purified and analysed by GC/FID or by HPLC/Fluorescence. Fourteen PAHs of two to six aromatic rings have been thus quantified. The two procedures are in agreement for the common species measured. The procedure using the analysis by HPLC/Fluorescence is both more selective and more sensitive. It allows an estimate to be made of the influence of load and speed on PAH emissions.