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This paper presents an overview of the results on light duty vehicles collected in the “PARTICULATES” project which aimed at the characterization of exhaust particle emissions from road vehicles. A novel measurement protocol, developed to promote the production of nucleation mode particles over transient cycles, has been successfully employed in several labs to evaluate a wide range of particulate properties with a range of light duty vehicles and fuels. The measured properties included particle number, with focus separately on nucleation mode and solid particles, particle active surface and total mass. The vehicle sample consisted of 22 cars, including conventional diesels, particle filter equipped diesels, port fuel injected and direct injection spark ignition cars. Four diesel and three gasoline fuels were used, mainly differentiated with respect to their sulfur content which was ranging from 300 to below 10 mg/kg.

A light-duty diesel vehicle with an oxidising catalyst exhaust after-treatment device was fuelled with reference diesel and run in a transient driving cycle (new European Driving Cycle). The particulate emissions were sampled from the diluted exhausts using an Electrical Low Pressure Impactor (ELPI) with separation of the particles according to aerodynamic size into 13-size levels ranging from 30 nm to 10 μm. The particles were collected on glass fibre filters used as substrates in the impactor. The particlulate mass collected for each size level was determined by weighing the filter prior and after sampling. Each filter was extracted in dichloromethane (DCM) in an ultrasonic bath. The obtained raw-extracts were thereafter fractionated in accordance to increasing polarity into two fractions (I-II) using an open tubular silica column. The fractions were chemically characterised using Gas Chromatography-Mass Spectrometry.