Problems Caused by Moisture in Gas Chromatographic Analysis of Headspace SPME Samples of Short-Chain Amines

Volatile amines are usually problematic compounds in sampling, sample pretreatment and gas chromatographic analysis due to their chemical characteristics (polarity, basicity and reactivity). Headspace solid-phase microextraction (SPME) Arrow sampling of aqueous samples were proven to be complicated since moisture in the headspace was also sorbed into the SPME sorbent and resulted in distorted or split peaks for the volatile amines. This was the case especially with old used sorbents not so much with the new ones. Volume of the water sample, sampling conditions, quality of the SPME sorbent and desorption conditions greatly influenced the concentration of water in the headspace and in the sorbent phase. This, in turn, affected the length of the water film in the column which determined the degree of peak splitting and distance between the split amine peaks (water film trapped part of the amine molecules). Addition of the salt to the sample solution and additional drying of the SPME sorbent after the sampling were shown to effectively decrease the amount of water in the headspace and in the sorbent phase. This combined effect of salt addition and drying step resulted in much better peak shapes and intensities for the amines. In the best cases, the peak splitting for the volatile amines could in this way be completely avoided.Peer reviewe

Characterization of free amino acids, bacteria and fungi in size-segregated atmospheric aerosols in boreal forest : seasonal patterns, abundances and size distributions

Primary biological aerosol particles (PBAPs) are ubiquitous in the atmosphere and constitute similar to 30% of atmospheric aerosol particle mass in sizes > 1 mu m. PBAP components, such as bacteria, fungi and pollen, may affect the climate by acting as cloud-active particles, thus having an effect on cloud and precipitation formation processes. In this study, size-segregated aerosol samples ( 10 mu m) were collected in boreal forest (Hyytiala, Finland) during a 9-month period covering all seasons and analysed for free amino acids (FAAs), DNA concentration and microorganism (bacteria, Pseudomonas and fungi). Measurements were performed using tandem mass spectrometry, spectrophotometry and qPCR, respectively. Meteorological parameters and statistical analysis were used to study their atmospheric implication for results. Distinct annual patterns of PBAP components were observed, late spring and autumn being seasons of dominant occurrence. Elevated abundances of FAAs and bacteria were observed during the local pollen season, whereas fungi were observed at the highest level during autumn. Meteorological parameters such as air and soil temperature, radiation and rainfall were observed to possess a close relationship with PBAP abundances on an annual scale.Peer reviewe

Sesquiterpenes and oxygenated sesquiterpenes dominate the VOC (C-5-C-20) emissions of downy birches

Biogenic volatile organic compounds (BVOCs) emitted by the forests are known to have strong impacts in the atmosphere. However, lots of missing reactivity is found, especially in the forest air. Therefore better characterization of sources and identification/quantification of unknown reactive compounds is needed. While isoprene and monoterpene (MT) emissions of boreal needle trees have been studied quite intensively, there is much less knowledge on the emissions of boreal deciduous trees and emissions of larger terpenes and oxygenated volatile organic compounds (OVOCs). Here we quantified the downy birch (Betula pubescens) leaf emissions of terpenes, oxygenated terpenes and green leaf volatiles (GLVs) at the SMEAR II boreal forest site using in situ gas chromatographs with mass spectrometers. Sesquiterpenes (SQTs) and oxygenated sesquiterpenes (OSQTs) were the main emitted compounds. Mean emission rates of SQTs and OSQTs were significantly higher in the early growing season (510 and 650 ng g(dw)(-1) h(-1), respectively) compared to in the main (40 and 130 ng g(dw)(-1) h(-1), respectively) and late (14 and 46 ng g(dw)(-1) h(-1), respectively) periods, indicating that early leaf growth is a strong source of these compounds. The emissions had a very clear diurnal variation with afternoon maxima being on average 4 to 8 times higher than seasonal means for SQTs and OSQTs, respectively. fi Caryophyllene and fi-farnesene were the main SQTs emitted. The main emitted OSQTs were tentatively identified as 14-hydroxy-beta-caryophyllene acetate (M = 262 g mol(-1)) and 6-hydroxy-beta-caryophyllene (M D 220 g mol(-1)). Over the whole growing season, the total MT emissions were only 24% and 17% of the total SQT and OSQT emissions, respectively. A stressed tree growing in a pot was also studied, and high emissions of ff -farnesene and an unidentified SQT were detected together with high emissions of GLVs. Due to the relatively low volatility and the high reactivity of SQTs and OSQTs, downy birch emissions are expected to have strong impacts on atmospheric chemistry, especially on secondary organic aerosol (SOA) production.Peer reviewe

Spatiotemporal variation and trends in equivalent black carbon in the Helsinki metropolitan area in Finland

In this study, we present results from 12 years of black carbon (BC) measurements at 14 sites around the Helsinki metropolitan area (HMA) and at one background site outside the HMA. The main local sources of BC in the HMA are traffic and residential wood combustion in fire-places and sauna stoves. All BC measurements were conducted optically, and therefore we refer to the measured BC as equivalent BC (eBC). Measurement stations were located in different environments that represented traffic environment, detached housing area, urban background, and regional background. The measurements of eBC were conducted from 2007 through 2018; however, the times and the lengths of the time series varied at each site. The largest annual mean eBC concentrations were measured at the traffic sites (from 0.67 to 2.64 mu g m(-3)) and the lowest at the regional background sites (from 0.16 to 0.48 mu g m(-3)). The annual mean eBC concentrations at the detached housing and urban background sites varied from 0.64 to 0.80 mu g m(-3) and from 0.42 to 0.68 mu g m(-3), respectively. The clearest seasonal variation was observed at the detached housing sites where residential wood combustion increased the eBC concentrations during the cold season. Diurnal variation in eBC concentration in different urban environments depended clearly on the local sources that were traffic and residential wood combustion. The dependency was not as clear for the typically measured air quality parameters, which were here NOx concentration and mass concentration of particles smaller that 2.5 mu m in diameter (PM2.5). At four sites which had at least a 4-year-long time series available, the eBC concentrations had statistically significant decreasing trends that varied from -10.4 % yr(-1) to -5.9 % yr(-1). Compared to trends determined at urban and regional background sites, the absolute trends decreased fastest at traffic sites, especially during the morning rush hour. Relative long-term trends in eBC and NOx were similar, and their concentrations decreased more rapidly than that of PM2.5. The results indicated that especially emissions from traffic have decreased in the HMA during the last decade. This shows that air pollution control, new emission standards, and a newer fleet of vehicles had an effect on air quality.Peer reviewe

Determination of short-chain aliphatic amines in environmental samples

Short-chain aliphatic amines (SCAA) are present in multiple different matrices in the environment at low concentration levels. SCAA are considered to be environmentally relevant compounds due to their role as precursors in the formation of carcinogenic N-nitrosoamines in various matrices and new particle formation in the atmosphere. SCAA are characteristically highly volatile, polar, reactive and basic compounds. Consequently, the quantitative determination of SCAA tends to be rather challenging. In the literature part of this thesis, different analytical methods used for the determination of SCAA in environmental samples are reviewed. The typical approach for the analysis of SCAA has been the use of derivatization techniques. Derivatization converts SCAA into less polar and less volatile form, which enables the use of conventional separation techniques, such as gas chromatography (GC) and high-performance liquid chromatography (HPLC). However, the methods involving derivatization can be quite time consuming, require the usage of excess reagents and are mainly applicable for the analysis of primary and secondary SCAA. To reduce the amount of reagent and solvent consumption, microextraction techniques have been implemented as part of the derivatization methods. For the analysis of free SCAA, mainly ion chromatography (IC) and GC have been used. In recent years, also novel online mass spectrometry techniques have been used for the determination of free SCAA in atmospheric air. In the experimental part of this thesis, a novel solid-phase microextraction (SPME) device called SPME Arrow was used for the extraction of free SCAA. Different SPME Arrow sorbent materials were tested, including commercial and custom sorbents, extraction conditions were optimized and the performance of SPME Arrow was compared to conventional SPME fiber. The developed method was applied for the determination of SCAA in wastewater samples and atmospheric air samples. In general, the performance of the custom sorbent coated SPME Arrow was not adequate due to the deterioration of coating, although the preliminary results indicated possible selectivity towards dimethylamine. Considering the commercial sorbent coated SPME devices, the SPME Arrow was better than the SPME fiber in terms of limit of quantification and performance in real sample analysis. When the SPME Arrow was used for wastewater sample analysis, no matrix interferences were observed, opposite to the results obtained with the SPME fiber. In addition, the SPME Arrow could be used for the determination of SCAA in atmospheric air samples following prior preconcentration by using denuder for sampling

Rakennusmateriaalien sisältämien PAH-yhdisteiden vaikutus sisäilman laatuun (PAHSIS)

Suomalaisissa rakennustuotteissa on käytetty varsin yleisesti polysyklisiä aromaattisia hiilivetyjä eli PAH-yhdisteitä sisältäviä lähtömateriaaleja kuten kivihiilipikeä, kivihiilitervaa ja kreosoottiöljyä. PAHyhdistepitoiset rakennustuotteet ovat tyypillisesti rakenteiden sisällä ja niiden vaikutukset sisäilmaan vaihtelevat hyvin paljon. On tavanomaista, että PAH-yhdistepitoiset materiaalit eivät aiheuta mitään havaittuja haittoja ja niiden olemassaolo selviää vasta rakenteita muista syistä avattaessa. Toisinaan PAH-yhdisteet kuitenkin aiheuttavat hajuhaittoja ja näihin liittyviä oireita. PAH-yhdistepitoisten rakennusmateriaalien sisäilmavaarallisuuden arviointiin käytetään Suomessa yleisesti virheellisesti PAH(16)-yhdisteille annettuja vaarallisen jätteen raja-arvoja (Vna 221/2013). Kyseiset raja-arvot on asetettu työ- ja ympäristöturvallisuuden näkökulmasta ja tarkoitettu yksinomaan rakennusten purkujätteen käsittelyn ja sijoituksen arviointiin. Kyseisiä raja-arvoja ei ole tarkoitettu rakennusten käytettävyyden arviontiin tai korjaustarpeen ja korjaustapojen määrittämiseen. Koska rakenteissa olevien PAH-yhdistepitoisten materiaalien aiheuttamien riskien arviointiin ei sisäilman rajaarvojen lisäksi ole ollut saatavilla kattavaa ohjeistusta, on edellä mainittuja materiaalipitoisuuden rajaarvoja käytetty, mikä on johtanut riskien yliarviointiin sekä toisinaan "kaiken purkavaan" toimintatapaan, jolla voi laajetessaan olla merkittävää kansantaloudellista vaikutusta. PAH-yhdistepitoisista rakennusmateriaaleista ja niiden päästöistä ei ole kansallisen rakennusterveyden näkökulmasta kirjoitettuja selvityksiä, ja kansainvälisestikin tietoa on niukasti; julkaistu tieto rakennusmateriaalien PAH-yhdistepäästöistä rajoittuu lähinnä tapauskuvauksiin. Ymmärrys PAH-yhdisteiden terveyshaitoista taas perustuu pitkälti 1900-luvun loppupuoliskolla julkaistuun toksikologiseen tietoon, ja epidemiologiseen näyttöön PAH-seosten haitoista liittyen työtehtäviin, joissa on altistuttu korkeille pitoisuuksille kuumissa prosesseissa syntyviä PAH-yhdistehuuruja. Näissä todellinen altiste sekä myös altistumisen mekanismi ovat eronneet merkittävästi rakennuksissa tapahtuvasta altistumisesta. Yli puolet Suomen työpaikoista on toimistotyyppisiä tai niihin rinnastettavia työpaikkoja. Koska PAHyhdisteitä esiintyy rakennusmateriaaleissa edelleen melko yleisesti, sisäilman kautta potentiaalisesti PAH-yhdisteille altistuvia työntekijöitä on varsin suuri joukko. Tämän tutkimuksen tarkoituksena oli tuottaa tietoa rakenteissa olevien PAH-yhdistepitoisten materiaalien aistinvaraisesti havaittavista ja mitattavista sisäilmavaikutuksista ja näiden yhteydestä materiaalin PAH-yhdistepitoisuuteen ja -yhdistekirjoon. Tutkimus oli luonteeltaan laadullinen ja siinä pyrittiin kartoittamaan materiaalin ja sisäilman PAH-yhdistepitoisuuksien lisäksi tarkasti myös muita materiaalin sisäilmahaittoihin vaikuttavia osatekijöitä. Kokeellisen osion lisäksi raporttiin on koottu kattavasti tietoa mm. PAH-yhdistepitoisten rakennusmateriaalien käytön historiasta ja käyttötavoista sekä muuta perustietoa PAH-yhdisteiden problematiikan arvioinnin tueksi. Tutkimuksen kokeellisessa osassa mitattiin myös PAH-yhdistepäästöjä todellisten vanhojen rakennuskohteiden rakenteista irrotetuista materiaalikappaleista koekammiossa. Laskennallisella tarkastelulla pystyttiin tuottamaan lisäarvoa kokonaisriskin tarkasteluun riskin aiheuttavan materiaalin selvittämiseksi laskennallisen SER-pintatuoton ja SER-kammiotuloksen vertailulla sekä todennäköisen PAH-yhdisteiden siirtymismuodon arvioimisella. Osana tutkimusta selvitettiin ajantasaisin menetelmin myös naftaleenin hajukynnys, jonka osalta kirjallisuustieto on ollut hyvin vaihtelevaa. Hajukynnykseen perustuva kriittisen materiaalipitoisuuden määritys todettiin kuitenkin soveltumattomaksi tarkastelumenetelmäksi. Tutkimuksen perusteella materiaalin PAH-yhdistepitoisuus ei korreloinut sisäilmasta mitattavien PAHyhdistepitoisuuksien kanssa; korkeakaan PAH-yhdistepitoisuus materiaalissa ei nostanut sisäilmapitoisuuksia, kun materiaali oli rakenteiden sisällä koskemattomassa tilassa. Sisäilman PAH-yhdistepitoisuudet olivat useimmissa kohteissa normaalitilanteessa hyvin matalia ja poikkeavat hajut vähäisiä, tai niitä ei havaittu lainkaan. Alipaineisuuden vaikutus sisäilmapitoisuuksiin oli tutkituissa kohteissa vähäinen. Sitä vastoin rakenteen avaaminen ja erityisesti PAH-yhdistepitoisen materiaalin rikkominen aiheutti tyypillisesti voimakkaita päästöjä, joiden suuruus oli riippuvainen materiaalin PAH-yhdistepitoisuudesta. Tulosten perusteella merkittävä altistuminen PAH-yhdisteille toimistotyyppisissä työympäristöissä rakennuksen normaalissa käyttötilanteessa on epätodennäköistä. Rakenteiden avaaminen ja purkutyö sitä vastoin voivat aiheuttaa merkittävääkin altistumista, mikäli työturvallisuudesta ja ympäristön suojaamisesta ei huolehdita. Tutkimuksen tulosten perusteella sisäilman naftaleenipitoisuus tai naftaleenille tyypillinen haju eivät yksinään sovellu rakennusmateriaaliperäisten PAH-yhdistepäästöjen indikaattoriksi, vaan lisäksi tulee arvioida muiden PAH-yhdisteiden, kuten fenantreenin pitoisuuksia ja PAH-yhdisteseoksille tyypillistä ”ratapölkyn” hajua. Projektin tuloksia voidaan hyödyntää sisäilmaongelmien ratkaisemisessa sekä korjaus- ja purkutarpeen arvioinnissa. Tulosten perusteella materiaalin PAH-yhdistepitoisuus ei kuvasta suoraan materiaalin aiheuttamaa haittaa, vaan haitan arvioinnissa on ensisijaisen tärkeää tutkia päästöriskiksi arvioitu materiaali, rakenne ja siihen kohdistuvat rasitustekijät kokonaisuutena. Epäiltyjen haittojen arvioinnissa voidaan käyttää tilojen normaaleissa käyttöolosuhteissa otettuja sisäilman PAH-yhdistenäytteitä. Näytteenotossa tulee huomioida mahdolliset toistuvat olosuhdevaihtelut esimerkiksi rakenteen lämpöolosuhteissa. Rakenteen lämpeneminen saattaa lisätä päästöjä merkittävästi. Tarvittaessa näytteenottoja tulee keskimääräisten päästötasojen arvioimiseksi toistaa eri olosuhteissa, esimerkiksi eri vuodenaikoina. Kirjallisuuden ja tutkimustulosten perusteella on esitetty etenemismalli PAH-yhdistepitoisten materiaalien haittojen ja tarpeellisten korjaustoimenpiteiden arvioimiseksi

Emissions of volatile organic compounds from Norway spruce and potential atmospheric impacts

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Comprehensive characterization of wintertime submicron aerosol in a Nordic town influenced by residential wood combustion, traffic and industrial sources

Anthropogenic particulate matter with sizes smaller than 1 μm (PM1) is a concerning air pollutant that can affect human health. In this study, we present PM1 measurements performed in a small town in northern Finland that is exposed to contrasting sources (residential wood burning, traffic, industrial activities). The study was conducted in winter 2021, with a mobile laboratory equipped with sophisticated on-line aerosol instrumentation. The results showed a significant increase in particulate mass and number concentrations from biomass burning in residential areas and town centre due to the high share of residences using biomass burning. Organics and equivalent black carbon (eBC) clearly dominated the PM1 composition during the highest pollution levels, followed by inorganics (sulfate, nitrate and ammonium). PAHs and a few elements (e.g. K, Cl, Zn) were as well higher during evening. A source apportionment confirmed the association between high PM1 values and biomass burning, even though the traffic contribution was also important. PM1 measurements at an industrial area showed an increase in sulfate, organics, eBC, and a few elements (e.g. Cl, Na, Fe), and characteristic size distributions. Simultaneous measurements of lung deposited surface area (LDSA) of particles showed the sourcespecificity of biomass burning, traffic and industrial emissions on LSDA size distributions. Overall, the results enlighten the impact of relevant pollution sources on Nordic towns air quality during the coldest months and show the importance to also consider the chemical composition, particle numbers, and LDSA in future air quality metrics

Effects of emission sources on the particle number size distribution of ambient air in the residential area

Particle size distribution is a major factor in the health and climate effects of ambient aerosols, and it shows a large variation depending on the prevailing atmospheric emission sources. In this work, the particle number size distributions of ambient air were investigated at a suburban detached housing area in northern Helsinki, Finland, during a half-year period from winter to summer of 2020. The measurements were conducted with a scanning mobility particle sizer (SMPS) with a particle size range of 16–698 nm (mobility diameter), and the events with a dominant particle source were identified systematically from the data based on the time of the day and different particle physical and chemical properties. During the measurement period, four different types of events with a dominant contribution from either wood-burning (WB), traffic (TRA), secondary biogenic (BIO), or long-range transported (LRT) aerosol were observed. The particle size was the largest for the LRT events followed by BIO, WB, and TRA events with the geometric mean diameters of 72, 62, 57, and 41 nm, respectively. BIO and LRT produced the largest particle mode sizes followed by WB, and TRA with the modes of 69, 69, 46, and 25 nm, respectively. Each event type had also a noticeably different shape of the average number size distribution (NSD). In addition to the evaluation of NSDs representing different particle sources, also the effects of COVID-19 lockdown on specific aerosol properties were studied as during the measurement period the COVID-19 restrictions took place greatly reducing the traffic volumes in the Helsinki area in the spring of 2020. These restrictions had a significant contribution to reducing the concentrations of NOx and black carbon originating from fossil fuel combustion concentration, but insignificant effects on other studied variables such as number concentration and size distribution or particle mass concentrations (PM1, PM2.5, or PM10)

Characteristics and source apportionment of black carbon in the Helsinki metropolitan area, Finland

Black carbon is emitted from the incomplete combustion of carbonaceous fuels and will detrimentally affect air quality, climate and human health. In this study, equivalent black carbon (eBC) concentrations were measured by using an aethalometer (AE33) at three different locations in the Helsinki metropolitan area, Finland from October 2015 to May 2017. One sampling site was located in an urban street canyon (SC, sampling period 18 months) and two of the sampling sites were located in suburban detached house (DH) areas (DH1, 13 months and DH2, 5 months). Based on the campaign averages, the eBC concentration levels were higher at the street canyon site (1690 ± 1520 ng/m3) than at the residential detached house areas (DH1 = 880 ± 1500 ng/m3 and DH2 = 1040 ± 2130 ng/m3). The contribution of eBC from fossil fuel (BCFF) and wood burning (BCWB) were estimated based on the spectral dependence of light absorption of different sources. The spectral behavior is described using absorption Ångström exponent (α) values for both fossil fuel (αFF) and wood burning (αWB) that were determined using concurrent wood burning tracer (levoglucosan) measurements. Based on the source apportionment, the contribution of BCWB to eBC was clearly higher at the detached house area sites DH1 (41 ± 14%) and DH2 (46 ± 15%) than at the urban street canyon site (15 ± 14%). A distinct seasonal dependency was observed in the eBC concentration levels at the detached house areas. The highest concentrations were detected during the cold seasons due to residential wood combustion. On the opposite, at the SC site, the concentration levels of eBC were rather constant throughout the campaign, being dominated by the BCFF emissions from close-by vehicular traffic. Substantial temporal and spatial variability in eBC concentrations and sources were observed within the Helsinki metropolitan area. eBC is shown to be closely tied to the characteristics of the measurement site, season, meteorological conditions and the time of the day.publishedVersionPeer reviewe