Simultaneous determination of carbonyl compounds and polycyclic aromatic hydrocarbons in atmospheric particulate matter by liquid chromatography–diode array detection–fluorescence detection

Simultaneous analysis of 24 carbonyl compounds (alkanals, unsaturated, dicarbonylic and aromatic aldehydes and ketones) derivatized with 2,4-dinitrophenylhydrazine and 16 polycyclic aromatic hydrocarbons (PAHs) using a photodiode-array (PDA) and a fluorescence (FL) detector in series is proposed.The separation is carried out with a reversed-phase column and gradient elution using four solvents (acetonitrile, water, tetrahydrofuran and methanol) in less than 35 min. Several critical pairs of carbonyl compounds with 3 and 4 carbon atoms and different functional groups, isomers of tolualdehyde, aromatic and aliphatic aldehydes were conditional on the gradient elution. Common pre-treatment for two groups of compounds consists in a step of extraction and derivatization in aqueous medium and a further clean-up using a polymeric phase SPE and concentration in a mixture of dichloromethane:methanol. A pre-concentration factor of 50 was achieved by this procedure. Acetone and formaldehyde blanks were minimized and remain controlled with a specific cleaning of glass material and washing the SPE cartridge.The limits of detection (LOD) ranged from 0.006 to 0.18 ng mL−1 for PAHs and from 2.4 to 10.1 ng mL−1 for carbonyl compounds and method precision was ≤15% for all analysed compounds. Recoveries were within the range of 95–104% for PAHs except for more volatile compounds (acenaphthene and fluorene) and within the range of 72–113% for carbonyl compounds. The method was applied in water-soluble fraction of PM10 (atmospheric particulate matter with an aerodynamic diameter less than 10 μm) and the spectral contrast technique was used in the identification of carbonyl compounds.