Extraction Of Organic Compounds Research Articles

Analysis of per- and polyfluoroalkyl substances (PFAS) in raw materials intended for the production of paper-based food contact materials – evaluating LC-MS/MS versus total fluorine and extractable organic fluorine

Per- and polyfluoroalkyl substances (PFAS) analysis has become crucial due to their presence in the environment, their persistence and potential health risks. These compounds are commonly used in food contact materials (FCM) as a coating to provide water and grease-repellent properties. One of the pathways for PFAS to enter the human body is either through direct consumption of contaminated food or indirectly through migration from FCM into food. The purpose of this study was to investigate where the initial contamination of paper FCM occurs. We analysed paper material consisting of fresh fibre and secondary materials, intended to produce food packaging for the presence of PFAS. The samples were extracted and analysed for 23 different PFAS substances using the targeted approach with LC tandem mass spectrometry (LC-MS/MS). This analytical technique detects specific, easily ionisable PFAS with high sensitivity. However, one drawback of this approach is that it allows the identification of less than 1% of the PFAS known today. For this reason, we used combustion ion chromatography (CIC) to determine the content of extractable organic fluorine compounds (EOF) and compare it to the total fluorine content. The targeted analysis using LC-MS/MS measured an average sum concentration of PFAS of 0.17 ng g−1 sample. Our research shows that the primary PFAS contamination happens during the recycling process since all of the samples in which the targeted PFAS were measured belonged to the secondary material. The most frequently detected analytes were PFOA and PFOS, detected in 90% and 62% of the samples, respectively, followed by PFBS (in 29% of the samples). CIC showed that measured PFAS via LC-MS/MS amount to an average of 2.7 × 10−4% of total fluorine content, whereas the EOF was under the LOD in all of the measured samples. This result highlights the complexity of the accurate determination of PFAS compounds, displaying what kind of information the chosen methods provide.

Bioinspired Synthesis of Magnetic Nanoparticles Based on Iron Oxides Using Orange Waste and Their Application as Photo-Activated Antibacterial Agents.

Magnetic nanoparticles based on iron oxides (MNPs-Fe) have been proposed as photothermal agents (PTAs) within antibacterial photothermal therapy (PTT), aiming to counteract the vast health problem of multidrug-resistant bacterial infections. We present a quick and easy green synthesis (GS) to prepare MNPs-Fe harnessing waste. Orange peel extract (organic compounds) was used as a reducing, capping, and stabilizing agent in the GS, which employed microwave (MW) irradiation to reduce the synthesis time. The produced weight, physical-chemical features and magnetic features of the MNPs-Fe were studied. Moreover, their cytotoxicity was assessed in animal cell line ATCC RAW 264.7, as well as their antibacterial activity against Staphylococcus aureus and Escherichia coli. We found that the 50GS-MNPs-Fe sample (prepared by GS, with 50% v/v of NH4OH and 50% v/v of orange peel extract) had an excellent mass yield. Its particle size was ~50 nm with the presence of an organic coating (terpenes or aldehydes). We believe that this coating improved the cell viability in extended periods (8 days) of cell culture with concentrations lower than 250 µg·mL-1, with respect to the MNPs-Fe obtained by CO and single MW, but it did not influence the antibacterial effect. The bacteria inhibition was attributed to the plasmonic of 50GS-MNPs-Fe (photothermal effect) by irradiation with red light (630 nm, 65.5 mW·cm-2, 30 min). We highlight the superparamagnetism of the 50GS-MNPs-Fe over 60 K in a broader temperature range than the MNPs-Fe obtained by CO (160.09 K) and MW (211.1 K). Therefore, 50GS-MNPs-Fe could be excellent candidates as broad-spectrum PTAs in antibacterial PTT. Furthermore, they might be employed in magnetic hyperthermia, magnetic resonance imaging, oncological treatments, and so on.

Evaluation of the Effect of Changing the Composition of Wastewater on Biological Treatment when Adding a Mixture of Sulfide Alkali for the Treatment of Petrochemical Wastewater

The influence of a pilot assessment based on the results of a change in the composition of wastewater on the quality of biological wastewater treatment when a sulfide alkali mixture is added to the feedstream of petrochemical enterprises is presented. It was found that the results of wastewater treatment at biological treatment plants are not affected by phenols in sulfide alkali wastewater. It was confirmed that activated sludge retains the ability to extract organic compounds without reference to the proportion of sulfide alkali effluents in the treated water.

Methanobacterium alkalithermotolerans sp. nov., a novel alkaliphilic and hydrogen-utilizing methanogen isolated from an alkaline geothermal spring (La Crouen, New Caledonia).

An anaerobic, hydrogenotrophic methane-producing archaeon was isolated from an alkaline thermal spring (42 °C, pH 9.0) in New Caledonia. This methanogen, designated strain CANT, is alkaliphilic, thermotolerant, with Gram-positive staining non-motile cells. Strain CANT grows autotrophically using hydrogen exclusively as an energy source and carbon dioxide as the sole carbon source (without the requirement of yeast extract or other organic compounds). It grows at 20-45 °C (optimum, 45 °C) and pH 7.3-9.7 (optimum, pH 9.0). NaCl is not required for growth (optimum 0 %) but is tolerated up to 1.5 %. It resists novobiocin, streptomycin and vancomycin but is inhibited by ampicillin and penicillin, among other antibiotics. The genome consists of a circular chromosome (2.2 Mb) containing 2126 predicted protein-encoding genes with a G+C content of 36.4 mol%. Phylogenetic analysis based on the 16S rRNA gene sequence indicated that strain CANT is a member of the genus Methanobacterium, most closely related to the alkaliphilic Methanobacterium alcaliphilum WeN4T with 98.5 % 16S rRNA gene sequence identity. The genomes of strain CANT and M. alcaliphilum DSM 3459, sequenced in this study, share 71.6 % average nucleotide identity and 14.0 % digital DNA-DNA hybridization. Therefore, phylogenetic and physiological results indicate that strain CANT represents a novel species, for which the name Methanobacterium alkalithermotolerans sp. nov. is proposed, and strain CANT (=DSM 102889T= JCM 31304T) is assigned as the type strain.

Effect of PBAT Biodegradable Mulch Film Extract on Seed Germination and Seedlings Metabolism of Tobacco

Poly(butylene adipate-co-terephthalate) biodegradable mulch film (PBAT-BMF) is gradually applied in agricultural production, but its potential ecological risks have not been studied so far. In this paper, methyl tert-butyl ether (MTBE) was used to extract organic compounds from PBAT-BMF to evaluate its effects on tobacco seed germination and seedling metabolism. The results showed that six organic compounds were found in the extract of PBAT-BMF, among which the content of diisopropylphenyl isocyanate was the highest at 557.27 μg g−1. A germination test showed that the extract scan inhibited the germination of tobacco seeds. The germination time was 1 d later than the control(CK), and the germination percentage and germination energy were non-significantly decreased by 2.50% and 1.00%. In contrast, the extracts significantly affected the root length, and seedlings height (p < 0.01), decreased by 0.24 cm and 0.28 cm, respectively. A metabolic analysis revealed that the extracts have a certain stress effect on tobacco seedlings and showed an up-regulating effect on soluble sugar, critical organic acid, biogenic amine, and down-regulating alkaloid, which indicated that the carbon and nitrogen metabolism pathway of the tricarboxylic acid cycle and alkaloid synthesis were disturbed. These results indicated that organic compounds extracted from PBAT-BMF had stress effects on germination and the growth of tobacco seeds, which significantly changed the metabolism pathway. This study can provide a theoretical basis for the development and application of PBAT-BMF.

Plant-based nanostructured silicon carbide modified with bisphosphonates for metal adsorption

Nanostructured silicon carbide possesses superior properties such as excellent hardness, high chemical stability, large surface area and good sintering ability at relatively low temperatures compared to bulk silicon carbide. However, its synthesis with conventional methods is still challenging. In the present study, we produced nanostructured silicon carbide from barley husks with a simple self-propagating high-temperature synthesis. Barley husks were chosen as the raw material because they are agricultural residues widely available and contain large amount of nanostructured silica suitable as a precursor in the synthesis. We studied the effect of two processes to valorize the barley husks on the extracted silica particles: burning in an industrial scale furnace to produce heat energy and pyrolysis to extract organic compounds as well as controlled calcination as a reference. The processing prior to the extraction affected morphology and composition of the nanostructured silica. The highest purity and surface area of 187 m2/g was obtained for the silica extracted from pristine barley husks through calcination. On the other hand, pyrolysis allows additional valorisation of the biomass by producing bio-based organic chemicals and still the silica particles with relatively high surface area, 105 m2/g, can be extracted. Nanostructured silicon carbide was produced from the extracted nanostructured silica with magnesiothermic reduction via self-propagating high-temperature synthesis. Nanostructured silicon carbide produced from silica particles undergone calcination had the highest surface area of 196 m2/g. Furthermore, it was functionalized with bisphosphonates to be used as a metal adsorbent and examined in adsorption of manganese from landfill water with pH 8. The functionalization of the silicon carbide with bisphosphonates increased the adsorption capacity by 32 % and the material was able to withstand at least 5 adsorption/desorption cycles.

Synthesis and Evaluation of Performance Characteristics Green Composites from Sustainable Fatty Chitosan Graft Copolymer with Acrylic Acid for Wastewater Treatment

Many chitosan adsorbent derivatives for metal ion adsorption have been developed by grafting novel functional groups on the chitosan chain, and these functional groups are combined with chitosan to improve sorption capability. The chemical structure of chitosan was characterized by the spectroscopy of Fourier Transform Infrared (FT-IR). The degree of N-deacetylation (DDA) was also calculated from FT-IR data. The use of bio sorbent chitosan-fatty acid derivatives makes it possible to extract both heavy metals and organic compounds. In this analysis, the grafting copolymer of fatty chitosan derivatives with acrylic acid polymer was synthesized using ceric ammonium nitrate, the redox nitric acid method under UV irradiation. Synthesized copolymers have been subjected to various analytical techniques such as X-ray diffraction (XRD), thermogravimetric analysis (TGA) and differential thermogravimetric analysis (DTA) to confirm the formation of copolymers and to research their thermal stability. The findings show the formation and strong chemical interaction between fatty chitosan derivatives and acrylic acid. Fatty Chitosan derivatives and prepared grafting copolymers have been treated with copper and chromium-containing metal solutions and the results have shown that fatty chitosan derivatives and prepared copolymers are excellent in the removal of heavy metals such as copper and chromium. Prepared compounds could therefore open the way for industrial wastewater treatment.

Сравнительный анализ методов исследования отложений копоти на местах пожаров

Introduction. Smokes are aerosols that contain sublimating substances and condensing vapors, as well as products of chemical and photochemical reactions. In addition to solid and liquid particles, they contain gaseous products of both complete and incomplete decomposition during combustion process, as well as nitrogen and the remains of unreacted oxygen during combustion. The aerosol substance of smoke that has settled on any surface is called soot, which often acts as an object of fire-technical expertise, and the aggregate of soot particles that form zones of various configurations is called smokiness. Goals and objectives. The aim of the work is to study soot and its components for the development of a comprehensive methodology for the study of fires in determining both the focus and the cause of the fire, as well as the pathways of the spread of hazardous factors of fire at different stages of fire development. The main task of the work is to determine the dependence of the qualitative and quantitative indicators of soot and its component composition on the temperature conditions of combustion of various materials in order to establish the conditions for the course of a fire. Research methods. Field and laboratory methods for the study of soot are considered. Field methods include visual analysis of soot deposits (identifying the configuration of soot, color and intensity of the soot layer) and measuring the electrical resistance of the soot layer using a field contact probe. Laboratory methods include the method of microscopic morphological analysis, the method of thermal analysis, molecular spectroscopy and gas chromatography, which are indirect and direct methods for studying extracted organic components of soot. Results and its discussion. The modern methods of research of soot are analyzed. A scheme of laboratory methods is proposed. It allows carry out full morphological analysis, to evaluate the behavior of soot components during heating and composition of extracted components for solving the problems of studying fires. Regression dependences of the content of bituminous components on the logarithm of the electrical resistance of the soot layer were obtained, which showed that, regardless of the type of combustible material, a transition zone is observed on them, in which, with a relatively small change in electrical resistance, a significant increase in the content of bituminous components is observed. Conclusion. The paper considers an comprehensive approach to the study of extractable components of soot. The obtained dependences of the qualitative and quantitative indicators of soot and its component composition on the temperature conditions of combustion of various materials will improve the quality and level of reliability of information in the study of fires in order to determine the focus and cause of a fire, as well as the ways of spreading hazardous factors of a fire at different stages of its development. Key words: smoke, soot, extractable organic compounds, bitumen components, soot layer electrical resistance, molecular spectroscopy, Boltzmann function, fire investigation.

Solid-Phase Microextraction Arrow for the Sampling of Volatile Organic Compounds in Milk Samples

A novel sample preparation method based on the use of the Arrow solid-phase microextraction device was used to extract and preconcentrate volatile organic compounds (VOCs) from milk samples prior to their determination by gas chromatography–mass spectrometry (GC-MS). The experimental parameters of the solid-phase microextraction (SPME) Arrow method were evaluated in terms of fiber type, sample volume, extraction temperature, extraction time, stirring rate and salt addition. Under the optimum extraction conditions, the SPME Arrow was compared with conventional SPME fibers to evaluate the effectiveness of the SPME Arrow method. Evaluation of the conventional SPME procedure was also performed under optimized conditions, for appropriate method comparison. Due to the larger sorption phase volume of SPME Arrow, a higher sensitivity and reproducibility were observed for the determined chromatographic peaks in comparison with conventional SPME fibers. The use of Carbon wide range (WR) SPME Arrow/polydimethylsiloxane (CAR/PDMS) SPME Arrow fibers leads to a compound-dependent improvement of a factor of 4–5x over the classical SPME setup. Moreover, the relative standard deviation (RSD) of the total volatiles for a conventional SPME procedure was 12.5%, while for SPME Arrow it was 6.2%. Finally, the novel method was successfully employed for the analysis of commercially available milk samples. The findings of this study indicate that SPME Arrow can be effectively used for the determination of volatile organic compounds in complex food matrixes.

Vienna soil organic matter modeler 2 (VSOMM2)

Soil Organic Matter (SOM) plays an important role in several biogeochemical processes by directly affecting the microbial activity, soil aggregation, plant growth and carbon storage. Despite of its importance, our understanding of its composition and structure is still incomplete. Several experiments using elemental analysis, nuclear magnetic resonance (NMR) and mass spectrometry (MS) shed light on the structure of organic matter. In this context, the Vienna Soil-Organic-Matter Modeler (https://somm.boku.ac.at/) is a website that generates condensed phase computer models of Soil-Organic-Matter (SOM). Most of the data comes from standardized samples by the International Humic Substances Association (IHSS), which uses a specific methodology to extract organic compounds from soil, called humic substances. We have improved the modeler by increasing the pool of elemental units that compose our SOM molecules called building blocks, and also by implementing a genetic algorithm that increases the chemical and geometric diversity of the models. This allowed us to create models using the IHSS data as well as different types of soil. The webserver uses as an input principally the elemental and organic composition and offers input files needed to run molecular dynamic (MD) simulations of solvated and neutralized SOM within the framework of the GROMOS 54A7 forcefield and the GROMOS and GROMACS simulation packages.

The antimicrobial activity of Serena repens (Saw Palmetto) extract against Burkholderia cepacia.

UMESH NEPALI & JOSEPH HORZEMPA, Department of Mathematics and Natural Sciences, West Liberty University, West Liberty, WV, 26074.The antimicrobial activity of Serena repens (Saw Palmetto) extract against Burkholderia cepacia. Burkholderia cepacia is a gram-negative bacterium and opportunistic human pathogen that most often causes pneumonia in individuals with weak immunity or underlying lung diseases such as Cystic Fibrosis. B cepacia is naturally drug resistant to numerous antibiotics. Therefore, to potentially identify novel antibiotics that inhibit the growth of B. cepacia, we previously screened a library of nearly 4000 extracts of plants, marine life, and fungi from the National Center for Natural Products Research. From this screen, Serena repens (Saw Palmetto) extract significantly inhibited the growth of B. cepacia. The purpose of this work is to validate the antimicrobial activity exhibited by Saw Palmetto extract, and to isolate and identify the compound(s) responsible for this activity. Both disk diffusion and time-to-kill assays will be used to test the antibiotic properties of Saw Palmetto extract. I have conducted pilot studies to optimize experimental conditions that will be used in these assays. Further, we will extract organic compounds from different parts of the Saw Palmetto plant. These extracts will be lyophilized, reconstituted, and then utilized in the bioassays to test antibiotic activity. Subsequently, extracts with activity will be separated by chromatography. To identify the active compounds, pure molecules showing antibiotic activity will be subjected to NMR and Mass Spectrometry. (Supported by NIH Grant P20GM103434 to the West Virginia IDeA Network for Biomedical Research Excellence)

Materials for Solid-Phase Extraction of Organic Compounds

This review provides an overview of the most recent developments involving materials for solid-phase extraction applied to determine organic contaminants. It mainly concerns polymer-based sorbents that include high-capacity, as well as selective sorbents, inorganic-based sorbents that include those prepared using sol-gel technology along with structured porous materials based on inorganic species, and carbon nanomaterials, such as graphene and carbon nanotubes. Different types of magnetic nanoparticles coated with these materials are also reviewed. Such materials, together with their main morphological and chemical features, are described, as are some representative examples of their application as solid-phase extraction materials to extract organic compounds from different types of samples, including environmental water, biological fluids, and food.

In vitro cellular toxicity induced by extractable organic fractions of particles exhausted from urban combustion sources - Role of PAHs

The bioactivity of the extractable organic matter (EOM) of particulate matter (PM) exhausted from major urban combustion sources, including residential heating installations (wood-burning fireplace and oil-fired boiler) and vehicular exhaust from gasoline and diesel cars), was investigated in vitro by employing multiple complementary cellular and bacterial assays. Cytotoxic responses were investigated by applying the MTT ((3-(4, 5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide)) bioassay and the lactate dehydrogenase (LDH) release bioassay on human lung cells (MRC-5). Sister Chromatids Exchange (SCE) genotoxicity was measured on human peripheral lymphocytes. Lipid peroxidation potential via reactive oxygen species (ROS) was evaluated on E. coli bacterial cells by measuring the malondialdehyde (MDA) end product. Furthermore, the DNA damage induced by the organic PM fractions was evaluated by the reporter (β-galactosidase) gene expression assay in the bacterial cells, and, by examining the fragmentation of chromosomal DNA on agarose gel electrophoresis. The correlations between the source PM-induced biological endpoints and the PM content in polycyclic aromatic hydrocarbons (PAHs), as typical molecular markers of combustion, were investigated. Fireplace wood smoke particles exhibited by far the highest content in total and carcinogenic PAHs followed by oil boilers, diesel and gasoline emissions. However, in all bioassays, the total EOM-induced toxicity, normalized to PM mass, was highest for diesel cars equipped with Diesel Particle Filter (DPF). No correlation between the toxicological endpoints and the PAHs content was observed suggesting that cytotoxicity and genotoxicity are probably driven by other extractable organic compounds than the commonly measured unsubstituted PAHs. Clearly, further research is needed to elucidate the role of PAHs in the biological effects induced by both, combustion emissions, and ambient air particles.

Comparison of different solid phase extraction sorbents for the qualitative assessment of dissolved organic nitrogen in freshwater samples using FT-ICR-MS

Fate and reactivity of dissolved organic matter (DOM) is directly linked to its chemical composition. Therefore, molecular characterisation, for example using Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS), is used for a better understanding of those factors. To study organic compounds in the water column, an efficient extraction method is important. The commonly used extraction method for FT-ICR-MS is solid phase extraction (SPE) using a reversed-phase sorbent (BondElut PPL). But this method, to the best of our knowledge, was not evaluated for its ability to extract organic nitrogen compounds which are important building blocks of life and therefore an important fraction of DOM. In this study, several solid phase sorbents were tested for their ability to extract organic nitrogen compounds from water samples of natural aqueous environments. Different cartridges concerning their retention mechanism and pore size were tested. Three cartridges with different extraction mechanism (reversed phase, cation exchange or a mixture of both) or different pore size were tested. Except for one sorbent type, which heavily contaminated the samples with organic molecules, the tested cartridges leached neither a significant amount of dissolved organic carbon (DOC) nor dissolved organic nitrogen (DON). The sorbents were tested with lake water to be able to investigate their functionality in real conditions. It could be shown, that the molecular composition of the sample should be considered for the choice of the sorbent material. Additionally, it was shown that a mixed-bed sorbent is a valuable complementary SPE sorbent for the molecular characterisation of lacustrine samples using FT-ICR-MS and it might also be useful for a quantitative extraction. Furthermore, it could be shown that HyperSep Retain CX sorbent allows to extract a broader range of organic nitrogen compounds leading to a more comprehensive data set for investigating organic nitrogen compounds in lakes using FT-ICR-MS.

Extraction of amino acids using supercritical carbon dioxide forin situastrobiological applications

AbstractThe detection of organic molecules that are indicative of past or present biological activity within the Solar System bodies and beyond is a key research area in astrobiology. Mars is of particular interest in this regard because of evidence of a (perhaps transient) warm and wet climate in its past. To date, space missions to Mars have primarily used pyrolysis technique to extract organic compounds from the Martian regolith, but it has not enabled a clear detection of unaltered native Martian organics. The elevated temperatures required for pyrolysis extraction can cause native Martian organics to react with perchlorate salts in the regolith, possibly resulting in the chlorohydrocarbons that have been detected by mass spectrometry, a commonly usedin situtechnique for space applications. Supercritical carbon dioxide (SCCO2) extraction technique is a powerful alternative to pyrolysis that may be capable of extracting and delivering unaltered native organic species to an analyser. In this study, we report the SCCO2extraction of unaltered amino acids (AAs) with simple laboratory analyses of extracts by capillary electrophoresis laser-induced fluorescence (CE/LIF) and liquid chromatography with mass spectrometry (LC/MS) techniques. The extraction efficiencies of several representative AAs using SCCO2with small amounts of pure water (~1–5%) as a co-solvent were determined. Glass beads were used as a model substrate to examine the effects of several experimental parameters and Johnson Space Center (JSC) Mars-1A Martian regolith simulant was used to study the effect of complex matrix on extraction efficiencies. With optimized experimental conditions (75C and 5% of water), extraction efficiencies from doped JSC Mars-1A were found to be ~40% for glycine, alanine and serine and ~10% for lysine. Extraction of native organics from undoped JSC Mars-1A suggests that SCCO2/water solvent system can extract both organics extractable with pure SCCO2and those extractable with pure water. Additionally, species not extracted by either pure SCCO2or pure water were extracted with SCCO2/water solvent. Despite the preliminary nature of this work, it paves the path for more comprehensive extraction studies of astrobiologically relevant samples with thorough analyses of resulting extracts.

Duck Potato Extract May Lead to the Inhibition of Biofilm Formation of Pseudomonas aeruginosa

Pseudomonas aeruginosa is a gram-negative bacterium that forms biofilms on many surfaces as well as within the lungs of cystic fibrosis (CF) patients. Pseudomonas biofilms are particularly dangerous because these structures protect bacteria from antibiotics and other chemical antimicrobial agents. Therefore, compounds that inhibit biofilm formation of P. aeruginosa are highly desired. In a separate study by our laboratory, we observed that Duck Potato extract (Sagittaria latifolia) exhibited antimicrobial activity on Clostridium perfringens, a pathogenic Gram-positive bacterium. Therefore, duck potato extract was evaluated to determine whether or not it was capable of inhibiting the growth of other pathogenic bacteria. Duck Potato plants were collected, the leaves were removed, and ethanol was used to extract organic compounds. The extracted material was added to a culture of P. aeruginosa. While duck potato extract did not inhibit the growth of this bacterium, a cursory analysis indicated that biofilm production was mitigated. We therefore conducted several microtiter-based biofilm studies to determine whether duck potato extract was capable of inhibiting the formation of Pseudomonas biofilms. Results showed that the Duck Potato extract did not directly kill the bacteria, however, this extract appeared to inhibit the biofilm formation of P. aeruginosa. (Supported by NIH Grant P20GM103434 to the West Virginia IDeA Network for Biomedical Research Excellence).

Prediction of Dispersive Liquid–Liquid Microextraction Enrichment Effect of Aromatic Organics by [OMIM] [PF6] Ionic Liquid Based on Atom-Type Electrotopological State Indices

In this work, a quantitative structure–property relationship (QSPR) model based on atom-type electrotopological state (E-state) indices has been developed for predicting the dispersive liquid–liquid microextraction (DLLME) enrichment effect for aromatic organics by using 1-octyl-3-methylimidazolium hexafluorophosphate ([OMIM][PF6]) ionic liquid as extractant. The enrichment factors of the aromatic organics obtained through DLLME-IL process were used as the dependent variable of the multiple linear regression (MLR) equation. The E-state indices of those organic compounds which combined together both electronic and topological characteristics of the analyzed molecules were used as molecular structure descriptors and the independent variable of the equation. The squared correlation coefficient R2 for the MLR was 0.992 for the training set of 33 compounds. For the test set of 8 compounds, the linear regression coefficient was R2 = 0.985. The results of this study showed that it can successfully predict enrichment factors of [OMIM][PF6] in DLLME by using atom-type E-state indices, which can provide one more way for predicting the ability of ionic liquid to extract organic compounds based on their molecular structures.

Impacts of Mesopotamian wetland re-flooding on the lipid biomarker distributions in sediments

Shallow sediment core samples from two locales in the Mesopotamian marshlands of Iraq were analyzed to characterize the extractable organic (lipid) compounds, and their sources and distributions after hydrological restoration by re-flooding of the marshes. Dried samples were extracted with a dichloromethane/methanol mixture before analysis by gas chromatography-mass spectrometry (GC–MS). The major compounds were n-alkanes, fatty acids and alcohols, steroids, terpenoids, hopanes, steranes, unresolved complex mixture (UCM), and plasticizers. The lipid compounds in Kurmashia (Al-Hammar marshes) were generally higher in concentration than in Abu Zirig (Central marshes), and decreased with core depths for both sites. This concentration decrease with core depth is attributed to transformation, biodegradation and variable input processes. The distribution patterns of the lipids in the sediment cores indicated that the Abu Zirig area was drier than Kurmashia before the re-flooding process. Furthermore, the concentration of the compounds in the surface sediment the Abu Zirig core was as high and similar to that in Kurmashia, reflecting the re-flooding impacts on the marsh and the revival of the wetland. The major sources of these lipids were from natural terrestrial vegetation (35–66% for Abu Zirig; 40–49% for Kurmashia), microbial (plankton) residues and bacteria (27–52% for Abu Zirig; 39–43% for Kurmashia), with a minor contribution from anthropogenic sources including plastic wastes and petroleum (6–13% for Abu Zirig; 9–18% for Kurmashia).

Extraction of organic compounds involved in the kinetic resolution of rac-2-pentanol from n-hexane by imidazolium-based ionic liquids: Liquid-liquid equilibrium

This paper focuses on the use of ionic liquids (1-butyl-3-methylimidazolium methylsulphate, [bmim+][MeSO4−], and 1-ethyl-3-methylimidazolium acetate, [emim+][Ac−]) to extract organic compounds involved in the racemic resolution of rac-2-pentanol (rac-2-pentanol, vinyl butyrate, rac-2-pentyl butyrate or butyric acid) from a mixture of one of these organic compounds with n-hexane. Liquid–liquid equilibrium data were experimentally obtained for seven ternary systems comprising an ionic liquid+rac-2-pentanol, vinyl butyrate, rac-2-pentyl butyrate or butyric acid+n-hexane at T=303.15K and atmospheric pressure. Binodal curves were measured applying the well-known procedure based on the observance of the cloud point while the compositions of the tie lines were calculated from refractive index and density measurements (the phase rich in the ionic liquid) and by gas cromatography (the phase rich in n-hexane). Selectivity values and the solute distribution ratio were utilized to test the possibility of the use of these ionic liquids as extractive solvents of the organic compounds implicated in the kinetic separation of the R- and S-enantiomers of rac-2-pentanol. The liquid-liquid equilibrium data of the ternary systems examined here have not previously been described in the literature.

Influence of continental organic aerosols to the marine atmosphere over the East China Sea: Insights from lipids, PAHs and phthalates

Total suspended particle (TSP) samples were collected during a marine cruise in the East China Sea from May 18 to June 12, 2014. They were analyzed for solvent extractable organic compounds (lipid compounds, PAHs and phthalates) using gas chromatography/mass spectrometry (GC/MS) to better understand the sources and source apportionment of aerosol pollution in the western North Pacific. Higher concentrations were observed in the terrestrially influenced aerosol samples on the basis of five-day backward air mass trajectories, especially for aerosols collected near coastal areas. Phthalates were found to be the dominant species among these measured compound classes (707±401ngm−3 for daytime and 313±155ngm−3 for nighttime), followed by fatty acids, fatty alcohols, n-alkanes and PAHs. In general, the daytime abundances for these compounds are higher than nighttime, possibly attributable to more intensive anthropogenic activities during the daytime. The factor analysis indicates that biomass burning, fungal activities and fossil fuel combustion maybe the main emission sources for organic aerosols over the East China Sea. This study demonstrates that the East Asian continent can be a natural emitter of biogenic and anthropogenic organics to the marine atmosphere through long-range transport, which controls the chemical composition and concentration of organic aerosols over the East China Sea.