title: FTIR analysis of surface functionalities on particulate matter produced by off-road diesel engines operating on diesel and biofuel.
abstract: Fourier transform infrared spectroscopy is applied as a powerful analytic technique for the evaluation of the chemical composition of combustion aerosols emitted by off-road engines fuelled by diesel and biofuels. Particles produced by burning diesel, heated rapeseed oil (RO), RO with ethylhexylnitrate, and heated palm oil were sampled from exhausts of representative in-use diesel engines. Multicomponent composition of diesel and biofuel particles reveal the chemistry related to a variety of functional groups containing carbon, hydrogen, oxygen, sulfur, and nitrogen. The most intensive functionalities of diesel particles are saturated C-C-H and unsaturated C=C-H aliphatic groups in alkanes and alkenes, aromatic C=C and C=C-H groups in polyaromatics, as well as sulfates and nitrated ions. The distinguished features of biofuel particles were carbonyl C=O groups in carboxylic acids, ketones, aldehydes, esters, and lactones. NO2, C-N and -NH groups in nitrocompounds and amines are found to dominate biofuel particles. Group identification is confirmed by complementary measurements of organic carbon (OC), elemental carbon, and water-soluble ion species. The relationship between infrared bands of polar oxygenated and non-polar aliphatic functionalities indicates the higher extent of the surface oxidation of biofuel particles. Findings provide functional markers of organic surface structure of off-road diesel emission, allowing for a better evaluation of relation between engine, fuel, operation condition, and particle composition, thus improving the quantification of environmental impacts of alternative energy source emissions.
authors.affiliation: Skobeltzyn Institute of Nuclear Physics, Lomonosov Moscow State University, 119991, Moscow, Russia, olga.popovicheva@gmail.com.
authors.forename: Olga B
authors.initials: OB
authors.lastname: Popovicheva
authors.forename: Elena D
authors.initials: ED
authors.lastname: Kireeva
authors.forename: Natalia K
authors.initials: NK
authors.lastname: Shonija
authors.forename: Michal
authors.initials: M
authors.lastname: Vojtisek-Lom
authors.forename: Jaroslav
authors.initials: J
authors.lastname: Schwarz
mesh_terms: D000336:Aerosols / Q000032:analysis; D000393:Air Pollutants / Q000032:analysis*; D056804:Biofuels / Q000009:adverse effects / Q000032:analysis*; D004784:Environmental Monitoring / Q000379:methods* / Q000706:statistics & numerical data; D005229:Fatty Acids, Monounsaturated; D005742:Gasoline / Q000009:adverse effects / Q000032:analysis*; D010084:Oxidation-Reduction; D000073878:Palm Oil; D052638:Particulate Matter / Q000032:analysis*; D010938:Plant Oils / Q000032:analysis; D000074262:Rapeseed Oil; D017550:Spectroscopy, Fourier Transform Infrared; D001335:Vehicle Emissions / Q000032:analysis*
chemical_list: D000336:Aerosols; D000393:Air Pollutants; D056804:Biofuels; D005229:Fatty Acids, Monounsaturated; D005742:Gasoline; D052638:Particulate Matter; D010938:Plant Oils; D000074262:Rapeseed Oil; D001335:Vehicle Emissions; D000073878:Palm Oil