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Organic compounds in atmospheric particulate matter above Maribor were analysed in 120 samples of PM10 sampled according to the EN 12341:2014 reference method. Organic compounds compositions were investigated together with the primary and secondary sources of air pollution. Silylation as derivatisation method was used for the GC-MS determination of volatile and semi-volatile polar organic compounds. Distribution of fatty acids, n-alkanes and iso-alkanes, phthalate esters, siloxanes, different sterols, various sugars and sugar alcohols, compounds of lignin and resin acids, dicarboxylic acids from photochemical reactions, PAHs, organic nitrogen compounds and products from secondary oxi- dation of monoterpenes were determined. The use of silicone grease for the purpose of lubricating the impact surface of the air sampler caused higher values of gravimetric determination. Solid particles may have been bounced from the surface of a greasy impact plate and re-entrained within the air stream and then collected on a sample filter. The carryover of siloxanes was at least from 5% up to 15% of the accumulated particles weight, depending on ambient temperature. This was the reason that the gravimetric results for determination of PM10 according to the standard EN 12341:2014 were overestimated. V 120 vzorcih PM10 smo analizirali organske spojine v aerosolskih delcih v zraku nad Mariborom z uporabo metode EN 12341:2014. Proučevali smo sestavo organskih spojin ter primarne in sekundarne izvore le-teh. Za določevanje hlapnih in delno hlapnih polarnih organskih spojin z GC-MS smo uporabili sililiranje kot derivatizacijsko metodo. Določevali smo porazdelitve maščobnih kislin, n-alkanov in izo-alkanov, ftalatnih estrov, siloksanov, različnih sterolov, različnih sladkorjev in sladkornih alkoholov, spojine ligninov in smolnih kislin, dikarboksilnih kislin nastalih s fotokemijskimi reakcijami, policikličnih organskih ogljikovodikov, organskih dušikovih spojin in produktov nastalih pri sekundarni oksidaciji monoterpenov. Uporaba silikonske masti na površini impaktne plošče vzorčevalnika lahko povzroči višje vrednosti gravimetrijske določitve. Trdni delci se lahko odbijejo od impaktne plošče in ponovno vstopijo v zračni tok in se nato zberejo na filtru. To prenašanje siloksanov je lahko najmanj od 5% do 15% skupne mase akumuliranih delcev v odvisnosti od temperature. To je razlog, da so gravimetrijski rezultati določevanja PM10 po EN 12341:2014 standardu previsoki. |
