Chemical markers for the characterization of bioaerosol

Bioaerosol is commonly defined as aerosolized particles, with a biological origin, spread into the air by a variety of abiotic and biotic mechanisms. The size of bioaerosol can range from several nanometers to a few hundred micrometres in aerodynamic diameter. Examples of bioaerosols include fungal and bacterial spores/cells, fungal hyphae, pollen, viruses and amoebae, algae, lichen, archaea, aggregates of these particles, and fragments of larger organisms including leaf litter, skin scales, animal and plant debris. Metabolites and excreta are also included in this topic. In these last years the knowledge about indoor and occupational bioaerosol exposure and related diseases has significantly increased. Biological particles have been linked to mucous membrane irritation, allergy, asthma, inflammatory lung diseases, hypersensitivity pneumonitis and so on . The use of biomarkers as a tool for the determination of bioaerosol has often been suggested. The basis of this approach is that bioaerosol components contain chemical compounds that can be used as markers of larger and/or bioactive structures. The main objective of our research is the identification and quantitation of dipicolinic and muramic acids, ergosterol, poliols, amino acids and proteins as markers of bacterial, fungal spores/cells and generic bioaerosol, in both indoor and outdoor airborne particulate matter. To achieve this purpose, methods of extraction and analysis by chromatographic techniques coupled to mass spectrometry of different classes of compounds from particulate matter of different size (ultrafine, fine and coarse), collected in proper sampling campaigns, have been developed

A liquid chromatography tandem mass spectrometry method for simultaneous analysis of 46 atmospheric particulate-phase persistent organic pollutants and comparison with gas chromatography/mass spectrometry,

A novel multi-analyte method for the simultaneous determination of 46 compounds of environmental concern, most of them belonging to the category of persistent organic pollutants, was developed using high-performance liquid chromatography and the results were compared to those obtained by gas chromatography. This study was performed in perspective of a cumulative exposure assessment of substances of health concern in environments where high levels, relatively to airborne particulate matter, can be found. The target compounds included polychlorinated biphenyls, brominated flame-retardants and derivatives of polycyclic aromatic hydrocarbons. The multi-analyte method was evaluated in air particulate matter in terms of reproducibility, linearity, recovery, limits of detection and quantification and matrix effect. The recovery was above 70% for all the analytes, whereas limits of quantification ranged between 23 and 390 pg.m(-3) in liquid chromatography and less than ten times in gas chromatography-mass spectrometry. Matrix effect was generally negligible for both the techniques, except the case of the detection of oxygenated derivatives of polycyclic aromatic hydrocarbons by gas chromatography

Liquid chromatography tandem mass spectrometry analysis of synthetic coccidiostats in eggs

Coccidiostats are synthetic drugs administered to animals, especially to poultry, to cure coccidiosis. In this paper, we present a selective liquid chromatography-tandem mass spectrometry (LC-MS/MS) method to analyze residues of five synthetic coccidiostats in eggs: clazuril, diclazuril, robenidine, nicarbazin, toltrazuril and its two metabolites. The extraction efficiency was evaluated by testing several solvents, pH, different volumes and time of extraction. The clean-up procedures were optimized using different solid phase extraction cartridges and different eluants. The chromatographic separation was achieved in reversed phase using a gradient of 0.1% formic acid in water and acetonitrile, whereas the MS detection was performed in negative electrospray ionization (ESI) for all the analytes, except for the robenidine. The developed method has been validated according to Commission Decision 2002/657/CE. The validation parameters, as linearity, precision, recovery, specificity, decision limit (CC alpha), detection capability (CC beta), and robustness have been determined. The proposed method resulted simple, fast, and suitable for screening and confirmation purposes

Determination of pesticides in the respirable fraction of airborne particulate matter by high-performance liquid chromatography–tandem mass spectrometry

Potential harmful effects of pesticides include risks to human health of workers involved in the wet spray application in cultivated areas. Inhalation exposure depends on several factors including pesticide concentrations in the respirable fraction of airborne particulate matter (PM4). To ensure a high level of protection, the use of tractors with cabins provides protection against dust, aerosols, and vapors. Since tractors not providing maximum protection are still in use, PM4 was sampled during spreading operations in agricultural fields inside and outside tractor cabins. Sample preparation technique based on accelerated solvent extraction and solid-phase extraction cleanup was optimized before analysis of nine pesticides in PM4. Meptyldinocap, deltamethrin, myclobutanil, fluopyram, methoxyfenozide, dimethomorph, fluopicolide, cyflufenamid, and metrafenone were simultaneously determined by high-performance liquid chromatography–electrospray ionization–tandem mass spectrometry (HPLC–ESI–MS–MS). The results demonstrated the efficacy of the tractor cabs used in the sampling sites. © 2017 Taylor & Francis

Determination of Sugar Content in Commercial Fruit Juices by Refractometric, Volumetric and Chromatographic Methods

In this paper several approaches are discussed for the direct analysis of the main sugars in different fruit juices. Refractometry, thin layer chromatography, volumetric analysis and high performance liquid chromatography with refractive index detector were tested and the results compared, discussing the advantages and disadvantages of each of them. Whereas the first method gives generically indications on the whole content of sugar and it doesn't require any prior manipulation of the sample, thin layer chromatography is useful only for qualitative purpose, on the other hand the third method, after removal of interferences, makes possible the determination of the reducing and not reducing sugar, and the last one allows the qualitative and quantitative determination of the saccharides singularly. It's very important to have not only knowledge about the chemical analysis of carbohydrates and their physicochemical properties, but especially how the methods can be used in product development for benefit of the public. In the wide range of options for the determination of the mono and disaccharides in beverages, the approach selected must be robust, accurate, powerful and reproducible

Monitoring alkylphenols in water using the polar organic chemical integrative sampler (POCIS): determining sampling rates via the extraction of PES membranes and Oasis beads

Polar organic chemical integrative samplers (POCIS) have previously been used to monitor alkylphenol (AP) contamination in water and produced water. However, only the sorbent receiving phase of the POCIS (Oasis beads) is traditionally analyzed, thus limiting the use of POCIS for monitoring a range of APs with varying hydrophobicity. Here a “pharmaceutical” POCIS was calibrated in the laboratory using a static renewal setup for APs (from 2-ethylphenol to 4-n-nonylphenol) with varying hydrophobicity (log Kow between 2.47 and 5.76). The POCIS sampler was calibrated over its 28 day integrative regime and sampling rates (Rs) were determined. Uptake was shown to be a function of AP hydrophobicity where compounds with log Kow < 4 were preferentially accumulated in Oasis beads, and compounds with log Kow > 5 were preferentially accumulated in the PES membranes. A lag phase (over a 24 h period) before uptake in to the PES membranes occurred was evident. This work demonstrates that the analysis of both POCIS phases is vital in order to correctly determine environmentally relevant concentrations owing to the fact that for APs with log Kow ≤ 4 uptake, to the PES membranes and the Oasis beads, involves different processes compared to APs with log Kow ≥ 4. The extraction of both the POCIS matrices is thus recommended in order to assess the concentration of hydrophobic APs (log Kow ≥ 4), as well as hydrophilic APs, most effectively. © 2017 Elsevier Lt

Toxic organic contaminants in airborne particles: levels, potential sources and risk assessment

In the last years, many studies have focused on risk assessment of exposure of workers to airborne particulate matter (PM). Several studies indicate a strong correlation between PM and adverse health outcomes, as a function of particle size. In the last years, the study of atmospheric particulate matter has focused more on particles less than 10 m or 2.5 m in diameter; however, recent studies identify in particles less than 0.1 m the main responsibility for negative cardiovascular effects. The present paper deals with the determination of 66 organic compounds belonging to six different classes of persistent organic pollutants (POPs) in the ultrafine, fine and coarse fractions of PM (PM < 0.1 m; 0.1 < PM < 2.5 mand 2.5 < PM < 10 m) collected in three outdoor workplaces and in an urban outdoor area. Data obtained were analyzed with principal component analysis (PCA), in order to underline possible correlation between sites and classes of pollutants and characteristic emission sources. Emission source studies are, in fact, a valuable tool for both identifying the type of emission source and estimating the strength of each contamination source, as useful indicator of environment healthiness. Moreover, both carcinogenic and non-carcinogenic risks were determined in order to estimate human health risk associated to study sites. Risk analysis was carried out evaluating the contribution of pollutant distribution in PM size fractions for all the sites. The results highlighted significant differences between the sites and specific sources of pollutants related to work activities were identified. In all the sites and for all the size fractions of PM both carcinogenic and non-carcinogenic risk values were below acceptable and safe levels of risks recommended by the regulatory agencies

Determination of the main bioaerosol components using chemical markers by liquid chromatography–tandem mass spectrometry

This work is part of an extensive research project aimed at the determination and characterization of bioaerosol with a multidisciplinary approach. In this context, one of the main objectives of the project has been the development of a comprehensive analytical method for the determination of different chemical biomarkers of the bioaerosol, by liquid chromatography coupled with tandem mass spectrometry. The following biomarkers have been considered, and correlated to specific components of bioaerosol as unambiguous indicators: • ergosterol fungal components • chlorophylls, phytosterols (stigmasterol and b-sitosterol), -tocoferol vegetable cells and algae • cholesterol animal cells, vegetable cells and algae. • dipicolinic acid bacterial spores • muramic and meso-2,6-diaminopimelic acid bacterial cells To verify the method, to find diagnostic ratios and to calculate the appropriate conversion factors, fungal spores, bacterial cells and spores, and algae of known species, commonly airborne, were analysed. The material was subjected to freezing and de-freezing cycles, followed by extraction, hydrolysis and purification of the biomarkers. The chromatographic separation of the bacterial biomarkers was achieved by using a polymeric column, based on Hydrophilic Liquid Interaction with the electrospray ionization mass spectrometric detection, whereas sterols and chlorophylls were separated by a reversed phase column, coupled to atmospheric pressure chemical ionization – tandem mass spectrometer. The optimized method was applied to environmental particulate matter sampled in an outdoor site. Bacterial and fungal content was compared to the results obtained from the classical direct viable counting method in the sampled particulate matte

Polychlorinated biphenyl profile in polyhydroxy-alkanoates synthetized from urban organicwastes

Call CIRC-05-2016The microbial synthesis of polyhydroxyalkanoates (PHA) from organic wastes is a valuable process to valorize available renewable resources, such as food wastes and biological sludge. Bioplastics find many applications in various sectors, from medical field to food industry. However, persistent organic pollutants could be transferred from wastes to the final product. The present paper demonstrates that the use of municipal wastes in PHA production is safe for the environment and human health and provides a polychlorinated biphenyl (PCB) profile in both commercial and waste-based PHA samples. PCB analysis in several PHA samples showed very low concentrations of the target analytes. Commercial PHA samples showed a similar PCB level with respect to PHA samples from municipal waste/sludge and higher than PHA samples from fruit waste. For all analyzed PCBs, detected concentrations were consistently lower than the ones reported in regulatory framework or guidelines.publishersversionpublishe

Toxic organic contaminants in airborne particles responsible for negative health effects

Several studies in literature have highlighted associations between airborne particulate matter and several adverse health outcomes, as a function of particle size. Traditionally, PM studies have focused on particles less than 10 μm in diameter (PM10) or particles less than 2.5 μm in diameter (PM2.5), with each fraction characterized by a distinct source, and different composition and health effects. Since, diffusion in the alveolar region of smaller particles with an aerodynamic diameter less than 0.1 μm (i.e. 100 nm and therefore also defined as nanoparticles) becomes an effective mechanism and the probability of deposition increases. There is a great debate whether ultrafine fraction (PM0.1) is mainly responsible for negative cardiovascular effects caused by its high oxidative and mutagenic potential. In the present study, size-fractionated airborne particulate matter was collected from outdoor urban and working environments and analyzed for 105 organic contaminants of different classes: polycyclic aromatic hydrocarbons (PAH) and their derivatives (nitro-PAH and oxy-PAH); polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and Novel Brominated flame-retardants (N-BFRs) selected for their toxicity and persistence in the environment. The selected organic contaminants were subsequently divided into three different macro-groups based on chemical and physical properties (PAH/N-PAH/O-PAH; PCB and PBDE/N-BFR) and subjected to statistical analysis. The monitoring campaigns were carried out in four sites: an urban atmosphere (RM), a wastewater treatment plant (WWTP) where aerosol is generated during the different phases of the processes, an intensive livestock farming activity, characterized by sheds serving as a shelter for cows (COW) and an area where feed is stored (FEED). In each monitoring campaign PM was collected with a multistage low-pressure impactor able to sample 14 size intervals of PM on as many filters, subsequently joined to form three dimensional fractions (coarse, fine and ultrafine). The results obtained from the organic contaminant analyses and from the Principal Component Analysis (PCA) showed a correlation between sites and classes of pollutants, allowing the identification of characteristic emission sources of each monitored site. Emission source studies are in fact a valuable tool for both identifying the type of emission source characteristic of a specific place and estimating the strength of each contamination source in the same place of interest