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The increase of volatile organic compounds (VOCs) emissions released into the atmosphere is one of the main threats to human health and climate. VOCs can adversely affect human life through their contribution to air pollution directly and indirectly by reacting via several mechanisms in the air to form secondary organic aerosols. In this study, aerial drone equipped with miniaturized air sampling systems including up to four solid-phase microextraction (SPME) Arrows and four in-tube extraction (ITEX) samplers for the collection of VOCs, along with portable devices for the real-time measurement of black carbon (BC) and total particle numbers at high altitudes was exploited. In total, 135 air samples were collected under optimal sampling conditions from October 4 to October 14, 2021 at the boreal forest SMEAR II Station, Finland. A total of 48 different VOCs, including nitrogen-containing compounds, alcohols, aldehydes, ketones, organic acids, and hydrocarbons, were detected at different altitudes from 50 to 400 m above ground level with the concentrations up to 6898 ng m-3 in gas phase and 8613 ng m-3 in particle phase. Clear differences in VOCs distribution were seen in samples collected from different altitudes, depending on the VOC sources. It was also possible to collect aerosol particles by the filter accessory attached on the ITEX sampling system, and five dicarboxylic acids were quantified with the concentrations of 0.43 to 10.9 µg m-3. The BC and total particle number measurements provided similar diurnal patterns, indicating their correlation. For spatial distribution, the BC concentrations were increased at higher altitudes being 2278 ng m-3 at 100 m and 3909 ng m-3 at 400 m. The measurements onboard the drone provided insights into horizontal and vertical variability in BC and aerosol number concentrations above the boreal forest.

Funding Information: Financial support was obtained from the Jane and Aatos Erkko Foundation and ACCC flagship “Finnish Research Flagship funded by the Academy of Finland (grant no. 337549 ). We thank Eka Dian Pusfitasari, Meri Sillanpää, Maria Andersson, Giorgia Demaria, Hangzen Lan, Nicola Zanca and Ilmari Heiskanen for their cooperation and valuable help. Publisher Copyright: © 2023 The Authors Solid phase microextraction Arrow and thermal desorption–gas chromatography–mass spectrometry allowed the collection and evaluation of volatile organic compounds (VOCs) emitted by fungal cultures from building insulation materials and in indoor air. Principal component analysis, linear discriminant analysis and supported vector machine were used for visualization and statistical assessment of differences between samples. In addition, a screening tool based on the soft independent modelling of class analogies (SIMCA) was developed for identification of fungal contamination of indoor air. Ten different fungal strains, incubated under ambient and microaerophilic conditions, were analyzed for time period ranging from 5 to 29 days after inoculation resulting in a total of 140 samples. In addition, the effect of additives on the fungal growing media was studied. The total number of compounds and concentration values were used for the evaluation of the results. Clear differences were observed for VOC profiles emitted by different fungal strains by exploiting long chain alcohols (3-octanol, 1-hexanol and 2-octen-1-ol) and sesquiterpenes (farnesene, cuprene). The analysis of glass-wool and cellulose based building insulation materials (3 samples) gave clear differences, mainly for oxygenated compounds (ethyl acetate and hexanal) and benzenoids (benzaldehyde). Moreover, the comparison of indoor air and insulation materials collected from a house with fungal indoor air problems indicated that 42% of the VOCs were found in both samples. The analysis of 52 indoor air samples demonstrated clear differences in their VOC profiles, especially for hydrocarbons, and between control (44 samples) and indoor air problem houses (8 samples). Finally, the SIMCA model enabled to recognize differences between control and fungi contaminated houses with a prediction capacity over 84%.

Large-sized mesoporous silica spheres loaded with different amounts of ZnO were prepared for the selective and efficient collection of nitrogen-containing compounds from air by in-tube extraction (ITEX) system. Commercial micrometer-sized chromatographic silica beads were modified using the pseudomorphic transformation approach to produce a material with narrow (2.7 nm) mesopores, while the spherical morphology of the particles was retained. The pores were infiltrated with zinc nitrate salt, which was converted to amorphous ZnO via mild thermal treatments at 300 °C. The ZnO infiltration process did not affect the morphology of the particles, but the available surface area decreased with each infiltration cycle. Sampling selectivity and efficiency were increased with the number of infiltration cycles, but problems related to the mechanical stability of the packed ITEX or backpressure were observed when the number of ZnO infiltration cycles was higher than 2. The large particle size of these materials (∼5.0 µm) decreased the backpressure on the ITEX without affecting the sampling selectivity and efficiency. Among nitrogen-containing compounds studied, sampling repeatability (n = 10) ranged between 2.4 (triethylamine) and 16.8% (isobutylamine). ITEX packing reproducibility (n = 3) ranged from 4.8 (pyridine) to 19.4% (isobutylamine). The performance of ITEX sampling devices packed with the material prepared was evaluated for targeted and untargeted analysis of nitrogen-containing compounds in air. Linear regression was used for their quantification in targeted analysis (r2 > 0.995), and the lowest LOD and LOQ values 6.6 and 21.8 ng l-1 were achieved for pyridine. Dipropylamine had the largest linear range from 23.6 to 3194.7 ng l-1. Partial least squared regression was used for the semi-quantification of the compounds identified using untargeted analysis (slope and bias equal to 1 and 0, respectively using full cross validation and Deming regression). The applicability of the ITEX systems with new sorbent materials for the analysis of nitrogen-containing compounds in indoor air, cigarette smoke and outdoor air was demonstrated. The lowest concentration was 0.7 ng l-1 for 1-nitropentane in outdoor air and the highest 1580.4 ng l-1 for acetonitrile in cigarette smoke.

The adsorption and desorption behavior of volatile nitrogen-containing compounds in vapor phase by solid-phase microextraction Arrow (SPME-Arrow) and in-tube extraction (ITEX) sampling systems, were investigated experimentally using gas chromatography-mass spectrometry. Three different SPME-Arrow coating materials, DVB/PDMS, MCM-41, and MCM-41-TP and two ITEX adsorbents, TENAX-GR and MCM-41-TP were compared to clarify the selectivity of the sorbents towards nitrogen-containing compounds. In addition, saturated vapor pressures for these compounds were estimated, both experimentally and theoretically. In this study, the adsorption of nitrogen-containing compounds on various adsorbents fol-lowed the Elovich model well, while a pseudo-first-order kinetics model best described the desorption kinetics. Pore volume and pore sizes of the coating sorbents were essential parameters for the deter-mination of the adsorption performance for the SPME-Arrow sampling system. MCM-41-TP coating with the smallest pore size gave the slowest adsorption rate compared to that of DVB/PDMS and MCM-41 in the SPME-Arrow sampling system. Both adsorbent and adsorbate properties, such as hydrophobicity and basicity, affected the adsorption and desorption kinetics in SPME-Arrow system. The adsorption and desorption rates of studied C6H15N isomers in the MCM-41 and MCM-41-TP sorbent materials of SPME-Arrow system were higher for dipropylamine and triethylamine (branched amines) than for hexylamine (linear chain amines). DVB/PDMS-SPME-Arrow gave fast adsorption rates for the aromatic-ringed pyridine and o-toluidine. All studied nitrogen-containing compounds demonstrated high desorption rates with DVB/PDMS-SPME-Arrow. Chemisorption and physisorption were the sorption mechanisms in MCM-41-and MCM-41-TP-SPME-Arrow, but additional experiments are needed to confirm this. An active sampling technique ITEX gave comparable adsorption and desorption rates on the selective MCM-41-TP and univer-sal TENAX-GR sorbent materials for all the compounds studied. Vapor pressures of nitrogen-containing compounds were experimentally estimated by using retention index approach and these values were compared with the theoretical ones, calculated using the COnductor-like Screening MOdel for Real Sol-vent (COSMO-RS) model. Both values agreed well with those found in the literature proving that these methods can be successfully used in predicting VOC's vapor pressures, e.g. for the formation of secondary organic aerosols.

Well-established label in biomolecules analysis, fluorescein isothiocyanate is commercially available in its two different isomers with equal fluorescence sensitivity, differing in meta- vs. para-isothiocyanate position. It was found in this study that the stability of the isomers depends on the polarity of different solvents and the pyridine (stabiliser) presence. The lowest stability has fluorescein isothiocyanate in water solvent. In acidic solution, their quinoid (acid) form switches to the lactone form. The p-quinoid form has higher tendency to create dimers and trimers and is less soluble in acetone than the lactone form. [GRAPHICS] .

Publisher Copyright: © 2022 The Authors There is a clear relationship between indoor air quality, gaseous compounds (volatile and semi-volatile) and particles emitted by building materials, biogenic and anthropogenic activities, and human health. An increased interest in indoor air quality and emissions has raised during recent years. Nowadays, it is possible to find several analytical approaches based on a wide variety of sampling and analytical techniques. The main objective of this review is to clarify the different options available for the analyst by a critical evaluation of the different steps involved in these methods. In this way, a clear description and evaluation of the potential advantages and shortcomings for the different devices required in materials emission studies, the collection of total air samples using air canisters and particles by vacuum surface have been included in this review. In addition, the potential use of active and passive sampling techniques, for the efficient collection of different compounds from the air samples is described. Then, the selection of the most adequate analytical approach for the analysis of different compounds as a function of their physicochemical properties is evaluated. The latter will include not only traditional approaches such as gas or liquid chromatography but also more sophisticated ones such as proton transfer reaction or chemical ionization mass spectrometry. Finally, the application of these different analytical approaches to the evaluation of indoor air emissions, mainly from biogenic and anthropogenic activities but also from different building materials, are introduced.

We have measured the changes in the production of volatile organic compounds (VOCs) by the oral pathogen Porphyromonasgingivalis, when treated in vitro with the antibiotic amoxicillin. We have also measured the VOC production of P.gingivalis grown in the presence and absence of supplemental hemin. Planktonic bacterial cultures were treated with different amounts of amoxicillin in the lag phase of the bacterial growth. Planktonic bacteria were also cultured with and without supplemental hemin in the culture medium. Concentrations of VOCs were measured with proton-transfer-reaction time-of-flight mass spectrometry (PTR-ToF–MS) and further molecular identification was done with gas chromatography–mass spectrometry (GC–MS) using solid phase microextraction (SPME) for sampling. The cell growth of P.gingivalis in the cultures was estimated with optical density measurements at the wavelength of 600 nm (OD600). We found that the production of methanethiol, hydrogen sulfide and several short- to medium-chain fatty acids was decreased with antibiotic treatment using amoxicillin. Compounds found to increase with the antibiotic treatment were butyric acid and indole. In cultures without supplemental hemin, indole and short- to medium-chain fatty acid production was significantly reduced. Acetic acid production was found to increase when supplemental hemin was not available. Our results suggest that the metabolic effects of both antibiotic treatment and supplemental hemin availability are reflected in the VOCs produced by P.gingivalis and could be used as markers for bacterial cell growth and response to threat. Analysis of these volatiles from human samples, such as the exhaled breath, could be used in the future to rapidly monitor response to antibacterial treatment.

Continuous flow quartz crystal microbalance (QCM) was utilized to study binding kinetics between EV subpopulations (exomere- and exosome-sized EVs) and four affinity ligands: monoclonal antibodies against tetraspanins (anti-CD9, anti-CD63, and anti-CD81) and recombinant intercellular adhesion molecule-1 (ICAM-1) or CD54 protein). High purity CD9+, CD63+, and CD81+ EV subpopulations of

Marinades are increasingly used to manufacture raw fish products. In corresponding meats, marinating is known to have a major effect on the composition of the microbiome, but the effect of marinating on fish is not known as well. This knowledge gap prompted our study of the microbial ecology and amine formation in marinated and unmarinated modified atmosphere commercially packaged rainbow trout fillet strips. According to our findings, marination increased the maximum concentrations (7-8 log CFU/g) of psychrotrophic bacteria by one loga-rithmic unit and led to 5 times higher average tyramine concentrations than the corresponding unmarinated product. Instead, trimethylamine concentrations were 30 times higher in the unmarinated product than those in the marinated one. According to the 16 S rRNA sequence analyses, lactic acid bacteria (LAB) predominated in the marinated strips one day after the use-by date, whereas in the unmarinated strips Fusobacteriaceae and LAB were the dominating taxa. Based on the culture-dependent analysis, Latilactobacillus fuchuensis was the prevailing LAB in both products. Since the subset of L. fuchuensis strains tested was able to produce tyramine in vitro, we hypothesise that the use of the acidic marinade activated the production of tyrosine-decarboxylating enzymes in L. fuchuensis and led to the increased tyramine concentrations.

Publisher Copyright: © 2021 The Authors The potential of using capillary electromigration techniques for biomimicking essential biological interactions is described. The most commonly used methodologies with their exploitation in calculations of kinetics and biomolecular interaction data are briefly discussed. Experimental approaches for bimolecular interactions with some selected examples, including lipoproteins, glycosaminoglycan, liposomes and some DNA or RNA interactions, are enlighted including the affinity constants for some selective important interactions. The review demonstrates that capillary electromigration techniques can be used as alternative biomimicking tools for the determination of important biological interactions. This review covers selected papers published in 2003-2021.

We have measured the volatile fingerprints of four pathogenic oral bacteria connected to periodontal disease and dental abscess: Porphyromonas gingivalis (three separate strains), Prevotella intermedia, Prevotella nigrescens and Tannerella forsythia. Volatile fingerprints were measured in vitro from the headspace gas of the bacteria cultured on agar. Concrete identification of new and previously reported bacterial volatiles were performed by a combination of solid phase microextraction (SPME) and offline gas chromatography–mass spectrometry (GC–MS). We also studied the effect of the reduced electric field strength (E/N) on the fragmentation patterns of bacterial volatiles in online proton-transfer-reaction time-of-flight mass spectrometry (PTR-ToF-MS). We aimed to discover possible new biomarkers for the studied oral bacteria, as well as to validate the combination of GC–MS and PTR-MS for volatile analysis. Some of the most promising compounds produced include: 1-Methyl-1,2,3,4-tetrahydroisoquinoline (1MeTIQ), indole, and a cascade of sulphur compounds, such as methanethiol, dimethyl disulphide (DMDS) and dimethyl trisulphide (DMTS). We also found that several compounds, especially alcohols, aldehydes and esters, fragment significantly with the PTR-MS method, when high E/N values are used. We conclude that the studied oral bacteria can be separated by their volatile fingerprints in vitro, which could have importance in clinical and laboratory environments. In addition, using softer ionization conditions can improve the performance of the PTR-MS method in the volatile analysis of certain compounds.

Primary biological aerosol particles (PBAPs) play an important role in the interaction between biosphere, atmosphere, and climate, affecting cloud and precipitation formation processes. The presence of pollen, plant fragments, spores, bacteria, algae, and viruses in PBAPs is well known. In order to explore the complex interrelationships between airborne and particulate chemical tracers (amino acids, saccharides), gene copy numbers (16S and 18S for bacteria and fungi, respectively), gas phase chemistry, and the particle size distribution, 84 size-segregated aerosol samples from four particle size fractions (< 1.0, 1.0–2.5, 2.5–10, and > 10 µm) were collected at the SMEAR II station, Finland, in autumn 2017. The gene copy numbers and size distributions of bacteria, Pseudomonas, and fungi in biogenic aerosols were determined by DNA extraction and amplification. In addition, free amino acids (19) and saccharides (8) were analysed in aerosol samples by hydrophilic interaction liquid chromatography–mass spectrometry (HILIC-MS). Different machine learning (ML) approaches, such as cluster analysis, discriminant analysis, neural network analysis, and multiple linear regression (MLR), were used for the clarification of several aspects related to the composition of biogenic aerosols. Clear variations in composition as a function of the particle size were observed. In most cases, the highest concentration values and gene copy numbers (in the case of microbes) were observed for 2.5–10 µm particles, followed by > 10, 1–2.5, and < 1.0 µm particles. In addition, different variables related to the air and soil temperature, the UV radiation, and the amount of water in the soil affected the composition of biogenic aerosols. In terms of interpreting the results, MLR provided the greatest improvement over classical statistical approaches such as Pearson correlation among the ML approaches considered. In all cases, the explained variance was over 91 %. The great variability of the samples hindered the clarification of common patterns when evaluating the relation between the presence of microbes and the chemical composition of biogenic aerosols. Finally, positive correlations were observed between gas-phase VOCs (such as acetone, toluene, methanol, and 2-methyl-3-buten-2-ol) and the gene copy numbers of microbes in biogenic aerosols.

Raman spectroscopy together with comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (GCxGC-TOFMS) was employed to characterize exomere- (

Our second generation air sampling drone system, allowing the simultaneous use of four solid phase microextraction (SPME) Arrow and four in-tube extraction (ITEX) units, was employed for collection of atmospheric air samples at different spatial and temporal dimensions. SPME Arrow coated with two types of materials and ITEX with 10% polyacrylonitrile as sorbent were used to give a more comprehensive chemical characterization of the collected air samples. Before field sampling, miniaturized samplers went through quality control and assurance in terms of reproducibility (RSD ≤14.1%, N = 4), equilibrium time (≥10 min), breakthrough volume (1.8 L) and storage time (up to 48 h). 128 air samples were collected under optimal sampling conditions from July to September 2019 at the SMEAR II station and Qvidja farm, Finland. 347 VOCs were identified in the air samples either on-site or in the laboratory by thermal desorption gas chromatography - mass spectrometry, and they were quantified/semiquantified using Partial Least Squares Regression models. Individual models were developed for the different coatings and packing materials using gas phase standards obtained by an automatic permeation system. Average gas phase VOC concentrations ranged from 0.1 (toluene, the SMEAR II station) to 680 ng L−1 (acetone, Qvidja farm). Average VOC concentrations in aerosols ranged from 0.1 (1,4-cyclohexadiene, the SMEAR II station) to 2287 ng L−1 (megastigma-4,6,8-triene, Qvidja farm). Clear differences in results were seen for samples collected at the SMEAR II station and Qvidja farm, between VOC compositions in gas phase and aerosols, and between the sampling site and height.

The research was done with partial filling micellar electrokinetic chromatography, microemulsion electrokinetic chromatography, and ultra-high performance liquid chromatography. The study focuses on determination of male and female steroids from cold and hot tap water of households in Helsinki City. The district ' s raw water is made run from Paijanne Lake through a water tunnel to the purification plants in Helsinki area. The effluents delivered from the plants to households as tap water were sampled and used for the study. They were concentrated with solid phase extraction to exceed the detection limits of the three methods. With partial filling method the limits were 0.50, 0.48, 0.33, and 0.50 mg/L for androsterone, testosterone, progesterone, and testosterone-glucuronide, respectively. In microemulsion method the limit values were 1.33, 1.11, and 0.40 mg/L for androsterone, testosterone, and progesterone, respectively, and 0.83, 0.45, and 0.50 mg/L for hydrocortisone, 17-alpha-hydroxyprogesterone, and 17-alpha-methyltestosterone, respectively. In the tap water samples, progesterone concentrations represented the highest values being 0.22 and 1.18 ng/L in cold and hot water, respectively. They also contained testosterone (in all samples), its glucuronide metabolite (in 25% of the samples), and androstenedione (in 75% of the samples). The ultra-high liquid chromatographic method with mass spectrometric detection was used for identification of the steroids at mu g/L level. (c) 2021 Elsevier B.V. All rights reserved.