Irena Grgić

National Institute of Chemistry · Department of Analytical Chemistry, Atmospheric Chemistry Group

Nitroaromatic compounds (NACs) as important constituents of atmospheric humic-like substances (HULIS) and brown carbon (BrC) affect the Earth's climate and pose a serious environmental hazard. We investigated seasonal size-segregated NACs in aerosol samples from the urban background environment in Ljubljana, Slovenia. Total concentrations of twenty...

Green plants exposed to abiotic or biotic stress release C-5 and C-6 unsaturated oxygenated hydrocarbons called Green Leaf Volatiles (GLVs). GLVs partition into tropospheric waters and react to form secondary organic aerosol (SOA). We explored the kinetics of aqueous-phase reactions of 1-penten-3-ol (PENTOL), (Z)-2-hexen-1-ol (HEXOL), and (E)-2-hex...

At present, there are still numerous unresolved questions concerning the mechanisms of light-absorbing organic aerosol (brown carbon, BrC) formation in the atmosphere. Moreover, there is growing evidence that chemical processes in the atmospheric aqueous phase can be important. In this work, we investigate the aqueous-phase formation of BrC from 3-...

Yellow-colored methylnitrocatechols (MNC) contribute to the total organic aerosol mass and significantly alter absorption properties of the atmosphere. To date, their formation mechanisms are still not understood. In this work, the intriguing role of HNO2 (catalytic and oxidative) in the dark transformation of 3-methylcatechol (3MC) under atmospher...

Methylnitrocatechols (MNCs) are secondary organic aerosol (SOA) tracers and major contributors to atmospheric brown carbon; however, their formation and aging processes in atmospheric waters are unknown. To investigate the importance of aqueous-phase electrophilic substitution of 3-methylcatechol with nitronium ion (NO2(+)), we performed quantum ca...

This Special Issue of Atmosphere, “Atmospheric Aqueous-Phase Chemistry”, comprises ten original articles dealing with different aspects of chemistry in atmospheric liquid water. Liquid water in cloud and fog droplets and in moist aerosol particles is ubiquitous in the atmosphere. Dissolved species from the soluble aerosol fraction, as well as solub...

C5- and C6- unsaturated oxygenated organic compounds emitted by plants under stress like cutting, freezing or drying, known as Green Leaf Volatiles (GLVs), may clear some of the existing uncertainties in secondary organic aerosol (SOA) budget. The transformations of GLVs are a potential source of SOA components through photo-oxidation processes occ...

Nitropolycyclic aromatic hydrocarbons (nitro-PAHs) are ubiquitous atmospheric pollutants whose increased concentration affects air quality and human health. It is known that they can be primary or secondary pollutants, and transformation reactions in the atmosphere are being increasingly studied. In this work, photodegradation of 1-nitropyrene, whi...

Atmospheric gases and particulate matter (PM) in contact with the material’s surface lead to chemical and physical changes, which in most cases cause degradation of the cultural heritage material. Atmospheric damage and soiling are recognized as two pivotal forms of deterioration of cultural heritage materials caused by air pollution. However, the...

Air pollution studies are still scarce in some areas in Europe like around the Adriatic Sea. Source apportionment of the fine particulate (PM2.5) organic aerosol (OA) was conducted near Rogoznica, a small touristic settlement on the Eastern Adriatic coast of Croatia, near Lake Rogoznica (43.53° N, 15.95° E). Filter-based offline analyses of PM by a...

The Atmosphere Special Issue “Atmospheric Aqueous-Phase Chemistry” comprises ten original articles dealing with different aspects of chemistry in atmospheric liquid water. [...]

Numerous green leaf volatiles (GLVs) are released into the atmosphere due to the stress, cell damage or wounding. Fog forming over vegetation takes up these compounds, promoting their aqueous-phase oxidation to less volatile compounds. The droplets eventually dry out, leaving behind the secondary organic aerosol (SOA). These pathways are still poor...

Fine particulate matter (PM2.5) concentrations at the Middle Adriatic coastal site of Croatia were affected by different air-mass inflows and/or local sources and meteorological conditions, and peaked in summer. More polluted continental air-mass inflows mostly affected the area in the winter period, while southern marine pathways had higher impact...

Fine particulate matter (PM2.5) concentrations at the Middle Adriatic coastal site of Croatia were affected by different air-mass inflows and/or local sources and meteorological conditions, and peaked in summer. More polluted continental air-mass inflows mostly affected the area in the winter period, while southern marine pathways had higher impact...

The ultimate goal in the understanding of complex chemical processes is a complete description of the underlying reaction mechanism. In the present study and for this purpose, a novel experimental platform is introduced that builds upon electrochemistry being able of generating reactive intermediate species at the electrode surface. The atmospheric...

Numerous green leaf volatiles (GLVs) are released into the atmosphere due to the stress, cell damage or wounding (Fisher et al., 2003; Jardine et al., 2015). Fog forming over vegetation takes up these compounds, promoting their aqueous-phase oxidation to less volatile compounds. The droplets eventually dry out, leaving behind the secondary organic...

Our current understanding of the importance of surface active substances (SAS) on atmospheric aerosol cloud-forming efficiency is limited, as explicit data on the content of size-resolved ambient aerosol SAS, which are responsible for lowering the surface tension (σ) of activating droplets, are not available. We report on the first data comprising...

Long-term measurements of carbon in HUmic-LIke Substances (HULIS-C) of ambient size-segregated water soluble organic aerosols were performed using a ten-stage low-pressure Berner impactor from December 2014 to November 2015 at an urban background environment in Ljubljana, Slovenia. The mass size distribution patterns of measured species (PM - parti...

A widely used instrument for collecting size-segregated particles is the micro-orifice uniform deposit impactor (MOUDI). In this work, a 10-stage MOUDI (cut-point diameter of 10μm to 56nm) was used to collect samples in Ljubljana, Slovenia, and Martinska, Croatia. Filters, collected with and without rotation, were cut in half and analyzed for nine...

A widely used instrument for collecting size-segregated particles is the micro-orifice uniform deposit impactor (MOUDI). In this work, a 10-stage MOUDI (cutpoint dia. 10 µm to 56 nm) was used to collect samples in Ljubljana, Slovenia and Martinska, Croatia. Filters, collected with and without rotation, were cut in half and analysed for nine element...

In recent studies, laser printers and photocopy machines have been identified as important sources of indoor air pollution with fine and ultrafine particles. In this work, the indoor pollution of a printing and photocopy center in Ljubljana, Slovenia was investigated. The particle number concentration time series and the particle size distributions...

The tropospheric aqueous-phase aging of guaiacol (2-methoxyphenol, GUA), a lignocellulosic biomass burning pollutant, is addressed in this work. Pathways of GUA nitration in aqueous solution under atmospherically relevant conditions are proposed and critically discussed. The influence of NaNO2 and H2O2, hydroxyl radical scavenger, and sunlight was...

The tropospheric aqueous-phase aging of guaiacol (2-methoxyphenol, GUA), a lignocellulosic biomass burning pollutant, is addressed in this work. Pathways of GUA nitration in aqueous solution under atmospherically relevant conditions are proposed and discussed from a kinetic perspective. Beside reactions with nitrite radicals (NO2•), nitronium ion (...

Aromatic compounds contribute significantly to the budget of atmospheric pollutants and represent considerable hazard to living organisms. However, they are only rarely included into atmospheric models which deviate substantially from field measurements. A powerful experimental-simulation tool for the assessment of the impact of low- and semi-volat...

A review of the techniques concerning the Molecular Identification of Organic Compounds in the Atmosphere is presented. An organic compound is fully identified only if its molecular structure is entirely known, including its isomeric and spatial (stereo) configuration. The first type of problem is when organic compounds need to be inventoried for t...

Guaiacol (2-methoxyphenol) and its derivatives can be emitted into the atmosphere by thermal degradation (i.e., burning) of wood lignins. Due to its volatility, guaiacol is predominantly distributed atmospherically in the gaseous phase. Recent studies have shown the importance of aqueous-phase reactions in addition to the dominant gasphase and hete...

Guaiacol (2-methoxyphenol) and its derivatives can be emitted into the atmosphere by thermal degradation (i.e. burning) of wood lignins. Due to its volatility, guaiacol is predominantly distributed in the atmospheric gaseous phase. Recent studies have shown the importance of aqueous-phase reactions in addition to the dominant gas-phase and heteroge...

For the first time, continuous aerosol measurements were performed in the Škocjan Caves, one of the most important cave systems in the world, and listed by UNESCO as a natural and cultural world heritage site since 1986. Measurements of PM10 were performed during three different periods: (1) in December 2011, the average background concentration wa...

Nitrogen-containing organic compounds in the atmosphere have drawn attention owing to their impact on aerosol chemistry and physics and their potential adverse effects on the biosphere. Among them, nitrocatechols and their homologs have recently been associated with biomass burning. In the present study, nitrocatechols, nitrophenols, nitroguaiacols...

Studying the chemical composition of biomass burning aerosol (BBA) is very important in order to assess their impact on the climate and the biosphere. In the present study, we focus on the characterization of some newly recognized biomass burning aerosol tracers including methyl nitrocatechols, nitroguaiacols and 4-nitrocatechol, but also on nitrop...

The fraction of pesticides lost in the atmosphere during and/or after treatments mainly enters the atmospheric particulate phase. However, little is known about the reactivity of these compounds when they are adsorbed on solid aerosol. Thus, reliable experimental procedures simulating atmospheric conditions are currently required in order to follow...

One of the largest primary sources of organic aerosols in the atmosphere is biomass burning (Laskin et al., 2009). The chemistry of compounds present in biomass burning aerosol (BBA) is diverse and directly dependent on the chemical composition of the burning material and the combustion conditions (Simoneit et al., 2002). A well-established tracer...

In this comment we want to draw attention to some weaknesses of the analytical method used for quantification of the organosulfates, which are influencing the end results, and thus the conclusions. We also try to suggest some possible improvements on the basis of our experience and knowledge.

A sensitive hydrophilic interaction liquid chromatography/electrospray ionization mass spectrometry (HILIC/ESI-MS/MS) method was developed for determination of selected aliphatic (i.e. malonic, succinic, glutaric, adipic, pimelic, suberic, azelaic, maleic, fumaric, glycolic and pyruvic acid), alicyclic (i.e. cis-pinonic and pinic acid) and aromatic...

Objective In this work, continuous and size-segregated aerosol measurements at Mt. Krvavec, Slovenia, during the Eyjafjallajökull volcanic eruption were performed. Based on chemical and morphological characteristics of size-segregated particles, the presence of the volcanic aerosols after long-range transport to Slovenia was to be confirmed. Resu...

The light-absorbing organic compounds present in and on condensed aerosol particles interacting with trace gases such as ozone can initiate a new and potentially important photo-induced multiphase chemistry. However, investigations of light induced multiphase processes are very scarce at present. We have launched the idea of pyruvic acid (PA) actin...

In this study for the first time it has been shown that pyruvic acid can affect the atmospheric multiphase reactions of ozone with oxalic acid due to its properties as a photosensitizer. To this end, the photochemical batch multiphase reactions of a mixture of pyruvic acid/oxalic acid (PA/OA) and gas-phase ozone under simulated sunlight were studie...

Atmospheric aerosols have important role in the biogeochemistry and transportation of metals in the atmosphere. On a mass basis, so called trace metals represent relatively small proportion of the atmospheric aerosol (generally less than 1 %). Among them are transition metals (TM) (e.g. Mn, Fe, Co, Cu), which have several oxidation states, and thus...

Size segregated sampling of aerosol particles at the coal-fired power station Šoštanj, Slovenia was performed by a newly developed system. In addition, simultaneous sampling of particles was performed at two locations, Velenje and Veliki vrh, chosen on the basis of long term monitoring of SO 2 in the influential area of power plant. The signature o...

This is a first attempt to measure the elemental mass loading in size-segregated aerosol particles using a laser ablation ICP-MS mapping approach in combination with image analysis software. For optimal mapping of impaction spots on foils the laser ablation ICP-MS parameters resolution, sensitivity and analysis time were critically balanced, depend...

The generally poor understanding of the formation of secondary organic aerosol (SOA) is a major source of uncertainty in predictions of aerosol concentrations and properties. Nevertheless, there is growing evidence that aqueous-phase oxidation reactions of water-soluble organics in cloud, fog and aqueous aerosol are a potentially important source o...

A special sampling system for measurements of size-segregated particles directly at the source of emission was designed and constructed. The central part of this system is a low-pressure cascade impactor with 10 collection stages for the size ranges between 15 nm and 16 microm. Its capability and suitability was proven by sampling particles atthe s...

A book "Environmental Chemistry of Aerosols" brings together the current state of knowledge of aerosol chemistry. The chapter "Metals in Aerosols" gives an overview of the current knowledge in the field of aerosols, which include also metal species. The chapter comprises topics like sources of metals in aerosols, physico-chemical characteristics,...

The rate constants for reactions of the SO 4 À radical anion with some low molecular weight monocarboxylic acids (MCAs) and dicarboxylic acids (DCAs) and their anions using the laser flash photolysis-long path laser absorption (LFP-LPLA) technique were determined. The present study contains the first measured rate constants for SO 4 À reactions wit...

During two campaigns in winter 2004, size segregated impactor samples (0.1-10 microm) and filter samples were taken in two Central European cities (Vienna, Austria and Ljubljana, Slovenia). The impactor samples were analyzed for major inorganic ions and short-chain organic acids, total carbon (TC) and black carbon (BC). Maximum concentrations of to...

Combustion processes result in generation of particles and gaseous products that create health and environmental risk. Therefore, information on the particulate matter emission from combustion sources is of great importance. Power plants are one of the largest point sources of particles; therefore the aim of our study was to characterize emissions...

Knowledge on the content and chemical composition of atmospheric aerosol particles provides an important information on the level of air pollution which has nowadays become a growing problem of the modern civilization. In the diploma thesis, mass distribution and chemical characterization of size segregated aerosol particles collected at three diff...

The chemical composition as well as the water uptake characteristics of aerosols was determined in size-segregated samples collected during November 2002 on the Slovenian coast. Major ions, water-soluble organic compounds (WSOC), short-chain carboxylic acids and trace elements were determined in the water-soluble fraction of the aerosol. Total aero...

The influence of some low weight mono- and di-carboxylic acids, which were selected on the basis of analysis of the water-soluble fraction of size segregated marine and urban aerosols collected in Slovenia, on the kinetics of S(IV) oxidation catalyzed by Mn(II) under conditions representative of tropospheric liquid water, was investigated. Mono-car...

The influence of some low weight mono-and di-carboxylic acids, which were selected on the basis of analysis of the water-soluble fraction of size segregated marine and urban aerosols collected in Slovenia, on the kinetics of S(IV) oxidation catalyzed by Mn(II) under conditions representative of tropospheric liquid water, was investigated. Mono-carb...

In the presence of hygroscopic material, stable aqueous droplets form at relative humidity below 100%. In this work, we examined the role and importance of NH 3 in SO 2 oxidation under haze conditions. Synthetic deposits composed mainly of NaCl and NaNO 3 were exposed to SO 2 /NH 3 /air gas mixture under controlled conditions, typical for heavily p...

The reaction kinetics of S(IV) autoxidation catalyzed by Mn(II) in the pH range 3–5 typical for atmospheric liquid water, was investigated. For reactions with pH maintained constant during the reaction course, the predictions obtained by a simple integral approach cover kinetic results only for concentrations of HSO 3 − up to 0.2 mM at pH 4.5. Thus...

. Aerosol particles are involved in many important atmospheric processes. One of the more important aerosol precursor is sulfur dioxide (SO2), which can be oxidized either in the gas phase or in the aqueous phase, yielding sulfuric acid gas or sulfates, respectively. The group was actively involved in project EUROTRAC-2 (EU 1489: "Transport and Tra...