Salivary lipid changes in young adult tobacco smokers and e-cigarette users: a hidden risk to oral health?

STUDY DESIGN: A cross-sectional, age- and gender-matched study was conducted to investigate the effects of different forms of nicotine delivery on salivary lipid profiles among young adult novice smokers compared to non-smokers. OBJECTIVE: To assess the effect of smoking traditional cigarettes, e-cigarettes, and heated tobacco products (HTPs) on the levels of specific sphingolipids (sphingosine, sphinganine, and sphingosine-1-phosphate), various ceramides, and lipid peroxidation products [malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE)] in both unstimulated and stimulated saliva samples collected from healthy young adults who had been smoking for 1-3 years and used only 1 of the 3 nicotine delivering methods. METHODS: Selection criteria included healthy young adults under 30 years old, with normal BMI and typical diet composition, and with no oral inflammatory lesions, orthodontic/dental appliances, or recent intake of medications or supplements. A total of 75 smokers and 25 non-smokers were enrolled in the study. Smokers were categorized into three groups, each comprising 25 individuals: traditional cigarette smokers, e-cigarette users, and HTPs smokers. Saliva samples were collected and analyzed for sphingolipid concentrations using ultra-high-performance liquid chromatography-tandem mass spectrometry. The concentrations of MDA and 4-HNE were measured using colorimetric and ELISA assays, respectively. RESULTS: The average smoking intensity in the traditional cigarette group was 10 cigarettes per day. Salivary sphingolipid and ceramides concentrations were significantly lower in smokers compared to non-smokers across all nicotine delivery methods (p < 0.0001). Moreover, traditional cigarette smokers exhibited higher levels of 4-HNE and MDA in both stimulated and unstimulated saliva, compared to non-smokers (p < 0.01). In stimulated saliva, both MDA and 4-HNE in e-cigarette users, and MDA in HTPs users, showed significantly lower concentrations than their comparators in traditional cigarette smokers (p < 0.01). CONCLUSION: Different nicotine delivery methods impact salivary lipid profile during the initial period of smoking habit. Reduced sphingolipids and elevated lipid peroxidation products suggest a disturbed lipid balance in the oral cavity due to enhanced oxidative stress within the salivary glands of novice smokers.

A selective chemiresistive sensor for the cancer-related volatile organic compound hexanal by using molecularly imprinted polymers and multiwalled carbon nanotubes.

A chemiresistive sensor is described for the lung cancer biomarker hexanal. A composite consisting of molecularly imprinted polymer nanoparticles and multiwalled carbon nanotubes was used in the sensor that is typically operated at a voltage of 4 V and is capable of selectively sensing gaseous hexanal at room temperature. It works in the 10 to 200 ppm concentration range and has a 10 ppm detection limit (at S/N = 3). The sensor signal recovers to a value close to its starting value without the need for heating even after exposure to relatively high levels of hexanal. Graphical abstract Schematic presentation of a chemiresistive sensor for detection of hexanal, a cancer biomarker. The hexanal-imprinted polymeric nanoparticles were synthesized, mixed with multiwalled carbon nanotubes and coated on the surface of an interdigitated electrode to produce a nanocomposite chemiresistor gas sensor for hexanal.

Extra virgin olive oil aroma release after interaction with human saliva from individuals with different body mass index.

BACKGROUND: The interindividual variability observed in saliva characteristics raises the question of its relationship with variability in fat sensory perception, particularly in aroma compounds. In the present study, which aimed to measure aroma release from different individuals, eleven key aroma compounds of extra virgin olive oil (EVOO) were monitored and quantified in dynamic headspace after an in vitro interaction between EVOO and human saliva. Therefore, 60 individuals were studied from those who were normal weight (NW), overweight (OW) and obese (O). RESULTS: OW and O demonstrate a higher release of C6 compounds compared to NW. By contrast, NW have a higher release of C5 compounds. Pentanal and hexanal also increased after saliva interaction in a refined olive oil that is free from volatiles. Among the saliva samples with a higher release in NW individuals, only pentanal was different. However, the low levels of these lipid oxidation end-products do not appear to be very important with respect to increasing odorous fat sensitivity. CONCLUSION: The results obtained in the present study demonstrate the important role of saliva in the aroma release of EVOO, indicating that humans can perceive it differently in relation to their body mass index. © 2017 Society of Chemical Industry.

An indoor air quality evaluation in a residential retrofit project using spray polyurethane foam.

Understanding of indoor air quality (IAQ) during and after spray polyurethane foam (SPF) application is essential to protect the health of both workers and building occupants. Previous efforts such as field monitoring, micro-chamber/spray booth emission studies, and fate/transport modeling have been conducted to understand the chemical exposure of SPF and guide risk mitigation strategies. However, each type of research has its limitation and can only reveal partial information on the relationship between SPF and IAQ. A comprehensive study is truly needed to integrate the experimental design and analytical testing methods in the field/chamber studies with the mathematical tools employed in the modeling studies. This study aims to bridge this gap and provide a more comprehensive understanding on the impact of SPF to IAQ. The field sampling plan of this research aims to evaluate the airborne concentrations of methylene diphenyl diisocyanate (MDI), formaldehyde, acetaldehyde, propionaldehyde, tris(1-chlor-2-propyl)phosphate (TCPP), trans-1-chloro-3,3,3-trifluoropropene (SolsticeTM), and airborne particles. Modifications to existing MDI sampling and analytical methods were made so that level of quantification was improved. In addition, key fate and transport modeling input parameters such as air changes per hour and airborne particle size distribution were measured. More importantly, TCPP accumulation onto materials was evaluated, which is important to study the fate and transport of semi-volatile organic compounds. The IAQ results showed that after spray application was completed in the entire building, airborne concentrations decreased for all chemicals monitored. However, it is our recommendation that during SPF application, no one should return to the application site without proper personal protection equipment as long as there are active spray activities in the building. The comparison between this field study and a recent chamber study proved surface sorption and particle deposition is an important factor in determining the fate of airborne TCPP. The study also suggests the need for further evaluation by employing mathematical models, proving the data generated in this work as informative to industry and the broader scientific community.

Comparison of tolerance of four bacterial nanocellulose-producing strains to lignocellulose-derived inhibitors.

BACKGROUND: Through pretreatment and enzymatic saccharification lignocellulosic biomass has great potential as a low-cost feedstock for production of bacterial nanocellulose (BNC), a high value-added microbial product, but inhibitors formed during pretreatment remain challenging. In this study, the tolerance to lignocellulose-derived inhibitors of three new BNC-producing strains were compared to that of Komagataeibacter xylinus ATCC 23770. Inhibitors studied included furan aldehydes (furfural and 5-hydroxymethylfurfural) and phenolic compounds (coniferyl aldehyde and vanillin). The performance of the four strains in the presence and absence of the inhibitors was assessed using static cultures, and their capability to convert inhibitors by oxidation and reduction was analyzed. RESULTS: Although two of the new strains were more sensitive than ATCC 23770 to furan aldehydes, one of the new strains showed superior resistance to both furan aldehydes and phenols, and also displayed high volumetric BNC yield (up to 14.78 ± 0.43 g/L) and high BNC yield on consumed sugar (0.59 ± 0.02 g/g). The inhibitors were oxidized and/or reduced by the strains to be less toxic. The four strains exhibited strong similarities with regard to predominant bioconversion products from the inhibitors, but displayed different capacity to convert the inhibitors, which may be related to the differences in inhibitor tolerance. CONCLUSIONS: This investigation provides information on different performance of four BNC-producing strains in the presence of lignocellulose-derived inhibitors. The results will be of benefit to the selection of more suitable strains for utilization of lignocellulosics in the process of BNC-production.

Impact of non-surgical periodontal therapy on saliva and serum levels of markers of oxidative stress.

OBJECTIVE: The purpose of this study was to determine the effect of non-surgical periodontal treatment on markers of oxidative stress in saliva and serum in patients with chronic periodontitis. MATERIALS AND METHODS: In total, 25 patients, who were diagnosed with generalized chronic periodontitis (11 females and 14 males), and 26 systemically and periodontally healthy individuals (15 females and 11 males) were included. The plaque index (PI), gingival index (GI), probing pocket depth (PPD), attachment loss (AL), gingival recession (GR), and bleeding on probing (BOP) were recorded at baseline and 6 weeks later. Malondialdehyde (MDA), 8-hydroxydeoxyguanosine (8-OHdG), and 4-hydroxy-2-nonenal (4-HNE) were assessed in saliva and serum samples before and after the non-surgical treatment by enzyme-linked immune sorbent assay (ELISA). RESULTS: In the group with chronic periodontitis, all clinical parameters were significantly higher compared to the control group at baseline (p < 0.001). Periodontal treatment reduced plaque, gingival inflammation, and pocket depth significantly (p < 0.001). At baseline, salivary 8-OHdG was significantly higher in chronic periodontitis (p < 0.001) and reduced significantly subsequent to the periodontal treatment (p < 0.001). Salivary MDA and serum 4-HNE were significantly higher in the patients with periodontitis compared to the control group (p < 0.001). Periodontal treatment did not significantly change the levels of 4-HNE and salivary MDA (p = 0.503, p = 0.093). CONCLUSIONS: Salivary 8-OHdG and MDA may be associated with local impact of periodontal disease, while 4-HNE may be associated with systemic impact of chronic periodontitis. CLINICAL RELEVANCE: Clinical intervention in periodontitis may be beneficial for periodontitis patients' systemic oxidative stress control, and using lipidic agents for the use of anti-inflammatory/pro-resolving processes for blocking the actions of arachidonic acid cascade can enable some late therapeutic strategies in order to lead oxidative stress-induced inflammation.

Characterization of chemical contaminants generated by a desktop fused deposition modeling 3-dimensional Printer.

Printing devices are known to emit chemicals into the indoor atmosphere. Understanding factors that influence release of chemical contaminants from printers is necessary to develop effective exposure assessment and control strategies. In this study, a desktop fused deposition modeling (FDM) 3-dimensional (3-D) printer using acrylonitrile butadiene styrene (ABS) or polylactic acid (PLA) filaments and two monochrome laser printers were evaluated in a 0.5 m3 chamber. During printing, chamber air was monitored for vapors using a real-time photoionization detector (results expressed as isobutylene equivalents) to measure total volatile organic compound (TVOC) concentrations, evacuated canisters to identify specific VOCs by off-line gas chromatography-mass spectrometry (GC-MS) analysis, and liquid bubblers to identify carbonyl compounds by GC-MS. Airborne particles were collected on filters for off-line analysis using scanning electron microscopy with an energy dispersive x-ray detector to identify elemental constituents. For 3-D printing, TVOC emission rates were influenced by a printer malfunction, filament type, and to a lesser extent, by filament color; however, rates were not influenced by the number of printer nozzles used or the manufacturer's provided cover. TVOC emission rates were significantly lower for the 3-D printer (49-3552 µg h-1) compared to the laser printers (5782-7735 µg h-1). A total of 14 VOCs were identified during 3-D printing that were not present during laser printing. 3-D printed objects continued to off-gas styrene, indicating potential for continued exposure after the print job is completed. Carbonyl reaction products were likely formed from emissions of the 3-D printer, including 4-oxopentanal. Ultrafine particles generated by the 3-D printer using ABS and a laser printer contained chromium. Consideration of the factors that influenced the release of chemical contaminants (including known and suspected asthmagens such as styrene and 4-oxopentanal) from a FDM 3-D printer should be made when designing exposure assessment and control strategies.

Center for the Polyurethanes Industry summary of unpublished industrial hygiene studies related to the evaluation of emissions of spray polyurethane foam insulation.

Spray polyurethane foam (SPF) insulation is used as thermal insulation for residential and commercial buildings. It has many advantages over other forms insulation; however, concerns have been raised related to chemical emissions during and after application. The American Chemistry Council's (ACC's) Center for the Polyurethanes Industry (CPI) has gathered previously unpublished industrial hygiene air sampling studies submitted by member companies that were completed during an eight-year period from 2007-2014. These studies address emissions from medium density closed cell and low density open cell formulations. This article summarizes the results of personal and area air samples collected during application and post application of SPF to interior building surfaces in both laboratory and field environments. Chemicals of interest included: Volatile Organic Compounds (VOCs), methylene diphenyl diisocyanate (MDI), flame retardants, amine catalysts, blowing agents, and aldehydes. Overall, the results indicate that SPF applicators and workers in close proximity to the application are potentially exposed to MDI in excess of recommended and governmental occupational exposure limits and should use personal protective equipment (PPE) consisting of air supplied respirators and full-body protective clothing to reduce exposure. Catalyst emissions can be reduced by using reactive catalysts in SPF formulations, and mechanical ventilation is important in controlling emissions during and after application.

Black phosphorus-assisted laser desorption ionization mass spectrometry for the determination of low-molecular-weight compounds in biofluids.

Quantitative analysis of small molecules by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has been a challenging task due to matrix-derived interferences in low m/z region and poor reproducibility of MS signal response. In this study, we developed an approach by applying black phosphorus (BP) as a matrix-assisted laser desorption ionization (MALDI) matrix for the quantitative analysis of small molecules for the first time. Black phosphorus-assisted laser desorption/ionization mass spectrometry (BP/ALDI-MS) showed clear background and exhibited superior detection sensitivity toward quaternary ammonium compounds compared to carbon-based materials. By combining stable isotope labeling (SIL) strategy with BP/ALDI-MS (SIL-BP/ALDI-MS), a variety of analytes labeled with quaternary ammonium group were sensitively detected. Moreover, the isotope-labeled forms of analytes also served as internal standards, which broadened the analyte coverage of BP/ALDI-MS and improved the reproducibility of MS signals. Based on these advantages, a reliable method for quantitative analysis of aldehydes from complex biological samples (saliva, urine, and serum) was successfully established. Good linearities were obtained for five aldehydes in the range of 0.1-20.0 µM with correlation coefficients (R (2)) larger than 0.9928. The LODs were found to be 20 to 100 nM. Reproducibility of the method was obtained with intra-day and inter-day relative standard deviations (RSDs) less than 10.4 %, and the recoveries in saliva samples ranged from 91.4 to 117.1 %. Taken together, the proposed SIL-BP/ALDI-MS strategy has proved to be a reliable tool for quantitative analysis of aldehydes from complex samples. Graphical Abstract An approach for the determination of small molecules was developed by using black phosphorus (BP) as a matrix-assisted laser desorption ionization (MALDI) matrix.

Mass spectrometric studies of fast pyrolysis of cellulose.

A fast pyrolysis probe/linear quadrupole ion trap mass spectrometer combination was used to study the primary fast pyrolysis products (those that first leave the hot pyrolysis surface) of cellulose, cellobiose, cellotriose, cellotetraose, cellopentaose, and cellohexaose, as well as of cellobiosan, cellotriosan, and cellopentosan, at 600°C. Similar products with different branching ratios were found for the oligosaccharides and cellulose, as reported previously. However, identical products (with the exception of two) with similar branching ratios were measured for cellotriosan (and cellopentosan) and cellulose. This result demonstrates that cellotriosan is an excellent small-molecule surrogate for studies of the fast pyrolysis of cellulose and also that most fast pyrolysis products of cellulose do not originate from the reducing end. Based on several observations, the fast pyrolysis of cellulose is suggested to initiate predominantly via two competing processes: the formation of anhydro-oligosaccharides, such as cellobiosan, cellotriosan, and cellopentosan (major route), and the elimination of glycolaldehyde (or isomeric) units from the reducing end of oligosaccharides formed from cellulose during fast pyrolysis.

Fast determination of aldehyde preservatives by miniaturized capillary electrophoresis with amperometric detection.

A novel miniaturized CE with amperometric detection (mini-CE-AD) method has been developed for fast determination of aliphatic aldehyde preservatives, namely formaldehyde and glyoxal, in commodities. After derivatization with an electroactive compound 2-thiobarbituric acid, these two nonelectroactive aldehydes were converted to electroactive adducts, therefore detectable by mini-CE-AD approach. Under the optimum conditions, two aldehydes can be well-separated with the coexisting interferents as well as their homologs (acetaldehyde and methyl-glyoxal), and the LODs (S/N = 3) were achieved at nanogram-per-milliliter level (1.64-2.80 ng/mL) based on the online enrichment method of transient moving chemical reaction boundary. The proposed method has been applied for the analyses of above aldehyde preservatives in different real commodity samples including skincare products, baby lotion, and toothpaste, and the average recoveries were in the range of 94-105%, which should find a wide range of analytical applications as an alternative to conventional and microchip CE approaches.

Non-targeted screening of extracts from polyester-phenolic can coatings: Identification of new aldehyde molecules from resole-based resins.

Phenolic and substituted phenol based resoles are commonly used in the formulation of can coatings. However, migration analyses of these coatings are very little described compared to other coating technologies. While epoxy and polyester have well known migrants with defined formation mechanisms, Non-Intentionally Added Substances (NIAS) specifically related to the phenolic resin are hardly studied in the literature. The goal of the publication is to further explore the influence of the phenolic resole, used in the formulation of can coatings, on extracted NIAS's nature. Six different model polyester-phenolic can coatings were formulated each with a specific phenol, cresol or tertbutylphenol-based resole. Can coating films were extracted for 24 h at 40 °C in acetonitrile before analysis. NIAS identification was done using gas chromatography separation coupled to high resolution mass spectrometry (HRMS) and nuclear magnetic resonance (NMR) spectroscopy analyses. Cyclic polyester oligomers were found in all extracts, with oligomers found in a range of 10 µg/dm2 to 226 µg/dm2, without specific influence of the resole used in formulation. While very few or no peaks were detected from cresol- and phenol-based resoles, 48 peaks were specifically observed in coating extracts of formulas with tertbutylphenol-based resoles as well as in their respective resoles. The most intense peaks were identified as aldehyde compounds by HRMS and NMR analysis. These aldehydes were semi-quantified in similar proportions as polyester oligomers. The presence of such aldehydes has never been reported in the literature regarding NIAS in can coatings. Further study will then be needed to better understand the aldehyde formation mechanism and assess the toxicological profile of such chemicals.

Self-Healing Hyaluronic Acid Nanocomposite Hydrogels with Platelet-Rich Plasma Impregnated for Skin Regeneration.

The development of natural hydrogels with sufficient strength and self-healing capacity to accelerate skin wound healing is still challenging. Herein, a hyaluronic acid nanocomposite hydrogel was developed based on aldehyde-modified sodium hyaluronate (AHA), hydrazide-modified sodium hyaluronate (ADA), and aldehyde-modified cellulose nanocrystals (oxi-CNC). This hydrogel was formed in situ using dynamic acylhydrazone bonds via a double-barreled syringe. This hydrogel exhibited improved strength and excellent self-healing ability. Furthermore, platelet-rich plasma (PRP) can be loaded in the hyaluronic acid nanocomposite hydrogels (ADAC) via imine bonds formed between amino groups on PRP (e.g., fibrinogen) and aldehyde groups on AHA or oxi-CNC to promote skin wound healing synergistically. As expected, ADAC hydrogel could protect and release PRP sustainably. In animal experiments, ADAC@PRP hydrogel significantly promoted full-thickness skin wound healing through enhancing the formation of granulation tissue, facilitating collagen deposition, and accelerating re-epithelialization and neovascularization. This self-healing nanocomposite hydrogel with PRP loading appears to be a promising candidate for wound therapy.

Understanding the volatile organic compounds of 1-methylcyclopropylene fumigation and packaging on yellow-fleshed peach via headspace-gas chromatography-ion mobility spectrometry and chemometric analyses.

Headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS) and chemometric methods were utilized to analyze changes in volatile organic compounds (VOCs) of yellow-fleshed peach by 1-methylcyclopropylene (1-MCP) treatment and modified atmosphere packaging (MAP). Meanwhile, the storage quality of yellow-fleshed peach at room temperature (25°C) was also studied. Yellow-fleshed peach was treated by four methods, namely, nanomaterial packaging (NA), 1-MCP fumigation and nanomaterial packaging (1-MCP-NA), polyethylene (PE) packaging, and 1-MCP fumigation with polyethylene packaging (1-MCP-PE). Changes in the decay rate, firmness, browning index, soluble solid content, and titratable acid of the fruit were then measured at room temperature at 1, 4 and 10 days of storage. Thirty-two VOCs, including terpenoids, alcohols, esters, aldehydes, and ketones, were identified. Seventeen VOCs were found to be significant with predictive variable important in the projection (VIP) > 1 and p < 0.05 by analysis of variance and orthogonal projection to latent structure discriminant analysis (OPLS-DA). After 10 days of storage, the browning index of 1-MCP-NA group was 51.7%, which was lower than the control fruit (PE, 76.7%). Compared with other three treatments, 1-MCP-NA showed the better ability to delay and inhibit decreases in ester and aldehyde contents, and the ethanol content was lowest in the samples treated by 1-MCP-NA during storage. Differences among treatment groups were distinguished by principal component analysis (PCA) and hierarchical clustering heat map. The results showed that 1-MCP-NA could well maintain the quality and flavor stability of yellow-fleshed peach, and it had a good application prospect in the postharvest preservation of yellow-fleshed peach. PRACTICAL APPLICATION: In this study, 1-methylcyclopropylene (1-MCP) combined with nanomaterial (NA) packaging (1-MCP-NA) proved to have a better fresh preservation effect. 1-MCP-NA showed better ability to delay and inhibit decreases in ester and aldehyde contents by HS-GC-IMS technique. It provided a new strategy for postharvest storage of yellow-fleshed peaches.

Identifying robust and reliable volatile organic compounds in human sebum for biomarker discovery.

Sebum from sebaceous glands is a rich source of volatile organic compounds (VOCs) that can readily be sampled non-invasively from the surface of skin. The VOC profiles of sebum can then be used to obtain information regarding different medical conditions including diabetes and Parkinson's Disease. However, the effects of sampling approaches and environmental factors on sebum VOC profiles are not established and the confident attribution of VOCs to disease states needs to be free of extraneous influences such as sampling materials and preparatory conditions. Here, we investigated a more standardised skin swab sampling approach for profiling sebum VOCs from healthy human subjects using thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS). Using a standard GC-MS method for the chemical analysis of sebum swabs, a surprisingly high number of VOCs originate from 'blank' medical swab material alone (up to 74 VOCs) and from the ambient environment (up to 29 VOCs) based on control experiments. We found that heat-treatment of medical swabs prior to GC-MS reduced the number of VOCs detected from 'blank' swabs and improved the reproducibility of VOC profiling, however significant VOC absorption can still occur from environmental exposure to ambient air. VOCs identified in 'blank' swabs consisted predominantly of hydrocarbons, esters, and silicon-based compounds and depended strongly on the material used (cotton and polyester-rayon). Environmental VOCs found to absorb to swabs from the ambient air during sampling included 1-butylheptyl-benzene and hexadecanoic acid methyl ester as well as exogenous VOCs such as isopropyl palmitate and isopropyl myristate. In contrast, sebum VOCs consisted primarily of esters, alcohols, ketones, and aldehydes. 23 and 18 VOCs were identified in sebum collected using polyester-rayon and cotton-based medical swabs, respectively, with 14 VOCs common to both swabs. The effect of subject bathing prior to sebum sampling had minimal impact on the VOC profiles. However, individual differences owing to external factors such as skin type, diet, and exercise will likely influence sebum production. This study highlights the importance of using rigorous controls in sebum sampling, and recommendations are provided for future research involving sebum VOC analysis. For example, the use of sebum sample replicates across multiple days, and the use of control swabs during sample collection is required to confirm the origin and reliability of sebum VOCs. It is anticipated that these recommendations in conjunction with a library of well-established VOCs from medical swabs will further strengthen biomarker identification resulting from sebum VOC analysis.

Lignin-derived phenols in Houston aerosols: implications for natural background sources.

Solvent-extractable monomeric methoxyphenols in aerosol samples conventionally have been used to indicate the influence of biomass combustion. In addition, the presence of lignin oxidation products (LOP), derived from the CuO oxidation of vascular plant organic matter, can help trace the source and inputs of primary biological particles in aerosols. Ambient aerosols (coarse and fine) collected in Houston during summer 2010 were analyzed by gas chromatography-mass spectrometry to characterize monomeric and polymeric sources of LOPs. This is the first time polymeric forms of the LOPs have been characterized in ambient aerosols. The absence or small concentrations of solvent-extractable monomeric LOPs and levoglucosan isomers point to the limited influence of biomass burning during the sampling period. The trace levels of anhydrosugar concentrations most likely result from long-range transport. This observation is supported by the absence of co-occurring lignin monomers that undergo photochemical degradation during transport. The larger concentration (142 ng m(-3)) of lignin polymers in coarse aerosols shows the relative importance of primary biological aerosol particles, even in the urban atmosphere. The LOP parameters suggest a predominant influence from woody tissue of angiosperms, with minor influence from soft tissues, gymnosperms, and soil organic matter.

Developing qualitative extraction profiles of coffee aromas utilizing polymeric ionic liquid sorbent coatings in headspace solid-phase microextraction gas chromatography-mass spectrometry.

Two solid-phase microextraction (SPME) sorbent coatings based on polymeric ionic liquids (PILs) have been utilized for the analysis of complex coffee aroma samples. The PIL-based SPME coatings examined, namely, poly(1-(4-vinylbenzyl)-3-hexadecylimidazolium bis[(trifluoromethyl)sulfonyl]imide) [poly(VBHDIm(+) NTf(2)(-))], with ~14-µm thickness, and poly(1-vinyl-3-hexylimidazolium chloride) [poly(ViHIm(+)Cl(-))], with ~8-µm thickness, were employed for the headspace determination of up to 49 analytes from four different coffee beans: two French roast coffees of different brands, Sumatra coffee, and decaffeinated Sumatra coffee. The analysis was conducted using gas chromatography coupled to mass spectrometry. For comparative purposes, the commercial polyacrylate (PA, 85-µm film thickness) SPME coating was utilized under the same extraction conditions. The three SPME coatings tested behaved quite differently as a function of the families of compounds extracted. Thus, the poly(VBHDIm(+) NTf(2)(-) ) coating was extremely selective for aldehydes while also exhibiting good extraction efficiencies for acids. The poly-(ViHIm(+) Cl(-)) coating exhibited superior performance for aromatic alcohols, and the PA coating worked better for heterocyclic aromatics. Both PIL-based SPME sorbent coatings demonstrated exceptional selectivity and extraction efficiency when dealing with complex coffee aromas in spite of their small film thicknesses.

Air pollution/working activity correlation: a case study in a dental hospital.

The paper deals with a multidimensional approach demonstrating a direct link between the entity of ongoing dentistry activity (number and kind of interventions) and specific pollution components. Simultaneously indoor/outdoor air concentrations of a set of volatile organic compounds (VOCs) and activity variables, describing the amount and nature of ongoing dentistry activities, were monitored over a year at a dental hospital located in an urban area. Principal Component Analysis (PCA) was used to single out mutually orthogonal pollution components which were then correlated to "pathology" factors arising from the analysis of dentistry activity indexes. The use of a multidimensional perspective allowed us to obtain a statistically significant model of the link between level of pollution and dentistry activity. In particular, the correlation approach linking pollution results to pathological variables allows us to establish a causative link even in the presence of sub-threshold concentrations of pollutants.

Determination of low-molecular mass phenols in red wines: the influence of chips, staves and micro-oxygenation aging tank.

The aim of this study is to assess the use of polymeric cartridges with diode array detection to extract the main low-molecular mass phenolic compounds from red wine samples. This method expanded and improved permitted to quantify 20 compounds in red wines made and aged under different conditions. These conditions included aging in barrels and in tanks with chips or staves as well as micro-oxygenation. The study of wine development during its wood storage period and the compounds transferred from the wood to the wine during this period provide useful important information concerning the impact of wine aging methods on the chemical makeup of the resulting wines. The main compounds that differentiated wine aging systems were identified to be 5-hydroxymethyl-2 furaldehyde, gallic acid, p-hydroxybenzoic aldehyde, syringic acid and sinapic acid.

Extraction and characterisation of hemicelluloses from maize stem.

INTRODUCTION: Extraction and characterisation of hemicelluloses are very important for converting them into functional materials and chemicals. OBJECTIVE: To develop a method for isolation of hemicelluloses from all cell walls. METHODOLOGY: Sequential steps using 90% dioxane, 80% acidic dioxane, 100% dimethyl sulphoxide and 8% NaOH were used for extraction of the hemicellulosic preparations (H(1), H(2), H(3) and H(4)) from maize stem. Advanced NMR techniques were used for the analysis of native hemicelluloses. RESULTS: Hemicelluloses with high yieldd were isolated from all cell walls, and contained arabinoxylan as the major polysaccharide. H(3) was substituted by α-L-arabinofuranose, α-D-xylopyranose, and acetyl groups (degree of saturation = 0.12/0.09) at O-3/O-2 of xylan. H(4) had a long continuous side chain of arabinose residues, and associated closely with non-cellulosic glucose. The hemicelluloses formed more linkages with guaiacyl lignins, and some p-coumaric acids built a bridge between hemicelluloses and lignin in maize stem. CONCLUSION: This modified method is successful for the isolation of hemicelluloses with high yields from all cell walls of maize stem.