Polar Organic Compound Research Articles

Development of nitrogen-rich hierarchical porous carbon for high selective adsorption of methanol in multi-VOCs waste gas recovery processes

Methanol is a typical polar volatile organic compound that has been commonly used as a solvent in industrial processes and is considered as an important resource. It often appears with aromatic compounds in practical application scenarios. Conducting methanol and aromatic compounds recycle technology can provide us with a sustainable carbon source for fuels and materials well beyond the fleeting fossil fuel era. Post-synthesis modification (PSM) has been utilized to incorporate 3-amino-1,2,4-triazole (Atz) into ZIF-8, thereby enabling the derivation of mesopore structure and enhancement of nitrogen content in ZIF-8 derived carbon. With this method the obtained carbon exhibited a highly polarizable micro-mesoporous structure, resulting in high adsorption capacity for methanol adsorption at low concentrations. The experimental results showed that the VOCs adsorption on porous carbon is primarily dictated by its microporous structure at high pressure, and predominantly governed by the presence of nitrogen functional groups and the micro-mesoporous properties at low pressure. DFT theoretical analysis also showed that nitrogen functional group can improve the absorption capacity of methanol by adsorbents through changing the electron distribution and surface polarity of carbon-based materials. Finally, based on the emission properties that is low concentration and high volume of VOCs waste gas in industrial application, ZIF8-24-700 and BACs-36 materials (Wang et al., 2023) were used to further prove the feasibility of this technology under low VOCs concentration, which achieve recovery rates of 99 % for toluene and 95 % for methanol, respectively.

Hydrophobic MOFs for the efficient capture of highly polar volatile organic compound

Effective capture of polar volatile organic compounds under environmental conditions is a challenge owing to the adsorption competition between polar volatile organic compounds and water.

Preparation of sulfonic acid-functionalized polymeric ionic liquid-based magnetic adsorbent and its applications to diquat extraction

有效萃取复杂食品样品中的极性污染物是实现其准确测定的瓶颈,也是食品安全分析的难点。针对污染物的结构特点,设计和发展能与之产生特定作用的新型材料是高效萃取的关键。敌草快是一种广谱性除草剂,为碱性的阳离子有机化合物。该文以1-乙烯基咪唑和1,3-丙磺酸内酯为原料合成了磺酸功能化的离子液体,通过自由基聚合反应,将其固载至磁性纳米颗粒表面,得到磺酸功能化的聚(1-乙烯基-3-丙基磺酸基咪唑氯盐)修饰的磁性纳米颗粒(Poly([VPImi-SO3H][Cl])-MP)。采用红外光谱、扫描电镜、振动样品磁强计和热重分析等对其结构、形貌和磁性进行了表征。将其作为磁性固相萃取的吸附剂,萃取青菜中的敌草快。磺酸基的功能化使Poly([VPImi-SO3H][Cl])-MP的表面在一定pH下带有丰富的负电荷,与敌草快之间产生强的静电吸引作用,可实现对敌草快的有效萃取。对影响萃取效率的各种参数如溶液pH、吸附剂质量、吸附时间、解吸剂种类和体积等进行了优化。在优化条件下,结合磁性固相萃取和高效液相色谱技术,对方法的性能及适用性进行了考察。敌草快在0.2~20 μg/g内具有良好的线性(r=0.9981),检出限(S/N=3)和定量限(S/N=10)分别为0.09 μg/g和0.2 μg/g; 3个水平(0.5、1.0和2.5 μg/g)下的加标回收率为82.7%~97.5%,相对标准偏差为2.8%~5.0%(n=3)。结果表明,磺酸功能化的Poly([VPImi-SO3H][Cl])-MP能快速、有效地萃取敌草快,建立的方法能用于青菜中敌草快的准确测定。

ALTERNATIVES FOR THE PRODUCTION OF LEVULINIC ACID OBTAINED FROM BIOMASS

Levulinic acid is a reactive polar organic compound deemed as a building block for several products with relevant applications, replacing traditional substances in the petrochemical industry. Considered a platform molecule, levulinic acid is industrially produced from the acid hydrolysis of biomass – mainly plant-based – using hydrochloric or sulfuric acid in homogenous catalysis. However, considering the World Market for levulinic acid is expected to reach US$ 71.9 million in 2027, growing annually at 14.1%, and its applications in agriculture, pharmaceuticals, plasticizers, cosmetics, and food additives, the development of alternative production processes is sought. Hence, a survey was performed on publications considering the alternatives for biomass-based levulinic acid production processes: I) alternative homogenous catalysts to avoid using noble materials in the reactor; II) heterogeneous catalysis to facilitate and reduce the catalyst’s separation and recovery costs; III) ionic liquids, exploiting their high solvency, stability, and catalytic capacity. Additionally, biomass alternatives for obtaining levulinic acid are presented, showing that other agricultural residues and animal biomass options are being considered, targeting process flexibilization while reducing costs and producing derivatives at more competitive prices. Thus, it can be stated that levulinic acid is an important platform molecule for biorefineries’ economics, replacing fossil fuels with renewable raw materials.

Detection of pharmaceuticals in wastewater effluents\u2014a comparison of the performance of Chemcatcher\xae and polar organic compound integrative sampler

Chemcatcher® and POCIS passive sampling devices are widely used for monitoring polar organic pollutants in water. Chemcatcher® uses a bound Horizon Atlantic™ HLB-L sorbent disk as receiving phase, whilst the POCIS uses the same material in the form of loose powder. Both devices (n = 3) were deployed for 21 days in the final effluent at three wastewater treatment plants in South Wales, UK. Following deployment, sampler extracts were analysed using liquid chromatography time-of-flight mass spectrometry. Compounds were identified using an in-house database of pharmaceuticals using a metabolomics workflow. Sixty-eight compounds were identified in all samplers. For the POCIS, substantial losses of sorbent (11–51%) were found during deployment and subsequent laboratory analysis, necessitating the use of a recovery factor. Percentage relative standard deviations varied (with 10 compounds exceeding 30% in both samplers) between individual compounds and between samplers deployed at the three sites. The relative performance of the two devices was evaluated using the mass of analyte sequestered, measured as an integrated peak area. The ratio of the uptake of the pharmaceuticals for the POCIS versus Chemcatcher® was lower (1.84x) than would be expected on the basis of the ratio of active sampling areas (3.01x) of the two devices. The lower than predicted uptake may be attributable to the loose sorbent material moving inside the POCIS when deployed in the field in the vertical plane. In order to overcome this, it is recommended to deploy the POCIS horizontally inside the deployment cage.

Organic chemical characterization of size segregated particulate matter samples collected from a thermal power plant area

Kütahya city, a thermal power plant (TPPs) affected region of Turkey, has serious air quality problems like similar industrial regions of the world due to the emissions from three closely-located coal-fired TPPs, residential coal combustion along with the contribution of several industrial stacks. The organic chemical speciation of ambient size-segregated particulate matter (PM) was investigated during two seasons at two sites with different pollution characteristics (urban and rural). The ambient PM was collected using a high volume cascade impactor, with 6 stages: PM>10.2, PM10.2-4.2, PM4.2-2.1, PM2.1-1.3, PM1.3-0.69 and PM<0.69. Collected PM samples were extracted with organic solvents and the organic composition (Polycyclic aromatic hydrocarbons (PAHs), n-alkanes and carboxylic acids) was determined by GC-MS. Sources of the organic species were assessed using molecular PAH diagnostic ratios, carbon preference index and wax percentages. More than 70% of the PM-bound PAHs were quantified in submicron particles. Similarly, 34–42% of n-alkanes and approximately 30% of the carboxylic acids were found on the smallest particles. The main sources of the PM-bound organic species were considered as the anthropogenic emissions such as coal and biomass combustion and also vehicular emissions rather than the biogenic sources. Considerably high cancer risk levels were obtained through inhalation of PAHs. Seasonal variations and size distributions of the carboxylic acids and levoglucosan were also evaluated. Polar organic compound concentrations were higher in the summer period at both locations probably due to the higher sunlight intensity and temperature favoring their photochemical formation.

Best Paper Award.

Best Paper Award.

Metal-Organic Frameworks for Cultural Heritage Preservation: The Case of Acetic Acid Removal.

The removal of low concentrations of acetic acid from indoor air at museums poses serious preservation problems that the current adsorbents cannot easily address owing to their poor affinity for acetic acid and/or their low adsorption selectivity versus water. In this context, a series of topical water-stable metal-organic frameworks (MOFs) with different pore sizes, topologies, hydrophobic characters, and functional groups was explored through a joint experimental-computational exploration. We demonstrate how a subtle combination of sufficient hydrophobicity and optimized host-guest interactions allows one to overcome the challenge of capturing traces of this very polar volatile organic compound in the presence of humidity. The optimal capture of acetic acid was accomplished with MOFs that do not show polar groups in the inorganic node or have lipophilic but polar (e.g., perfluoro) groups functionalized to the organic linkers, that is, the best candidates from the list of explored MOFs are MIL-140B and UiO-66-2CF3. These two MOFs present the appropriate pore size to favor a high degree of confinement, together with organic spacers that allow an enhancement of the van der Waals interactions with the acetic acid. We establish in this work that MOFs can be a viable solution to this highly challenging problem in cultural heritage protection, which is a new field of application for this type of hybrid materials.

Grab and passive sampling applied to pesticide analysis in the São Lourenço river headwater in Campo Verde – MT, Brazil

ABSTRACTIn this study, the quality of surface water in the headwaters of São Lourenço River in Mato Grosso, Brazil, was evaluated in relation to contamination by pesticides. For this purpose, samples were collected between December 2015 and June 2016 by grab sampling and by passive sampling using an integrative polar organic compound sampler installed in the field during four 14-day cycles between March and June 2016. The analyses were performed by gas chromatography (CG/MS) and by liquid chromatography (UPLC-MS/MS). The results showed the detection of two pesticides (atrazine and pyraclostrobin) of the five analyzed by passive sampling and eight active principles among the 20 analyzed (malathion, diuron, carbofuran, carbendazim, trifluralin, imidacloprid, metolachlor, and acetamiprid) by grab sampling. The detection of 10 pesticides, even almost a decade after the beginning of a recovery process of the ciliary forest, confirms the headwaters' vulnerability to these contaminants and passive sampling proved to be an important tool in capturing small concentrations of pesticides constituting an interesting complement to grab sampling.

Effect of Dibutyltin Dichloride on the Partitioning Behavior of Surfactant,n-Butanol, Perchloroethylene, and Water

Organometallic compounds added to organic compounds are sometimes found in contaminated sites. An organometallic compound is considered a dense nonaqueous phase liquid (DNAPL); thus, applying conventional surfactant-enhanced aqueous-based remediation may not be effective. Consequently, density-modified displacement (DMD), which is a surfactant-based remediation approach that decreases the density contrast between the remedial solution and the mobilized nonaqueous phase liquid (NAPL) through butanol (BuOH) partitioning, has been introduced. This approach converts a DNAPL into a light NAPL (LNAPL). Partitioning of each component during DMD is a vital variable in achieving efficient remediation. This study aimed to determine the effect of dibutyltin dichloride (DBT) on the distribution of each component between the aqueous phase and NAPL during the treatment process. DBT behaved as a polar organic compound and increased the polarity of the NAPL. When compared to the experiment with perchloroethylene (PCE) alone, presence of DBT increased partitioning of BuOH and the anionic surfactant from the aqueous phase to the NAPL. Moreover, presence of the anionic surfactant in the NAPL combined with a negligible level of aqueous surfactant at equilibrium in the system appeared to increase the partitioning of BuOH into the NAPL. This study's finding can be applied to the DMD technique. It can be expected that, by adding a proper polar/ionic organic compound or surfactant, the aqueous BuOH can be adequately reduced, thereby easing the transformation of the DNAPL into an LNAPL at the turning point in the DMD process.

Mass fraction assignment of folic acid in a high purity material

The comparison required the assignment of the mass fraction of folic acid present as the main component in the comparison sample. Performance in the comparison is representative of a laboratory's measurement capability for the purity assignment of organic compounds of medium structural complexity [molecular weight range 300–500] and high polarity (pKOW < −2).Methods used by the eighteen participating NMIs or DIs were based on a mass balance (summation of impurities) or qNMR approach, or the combination of data obtained using both methods. The qNMR results tended to give slightly lower values for the content of folic acid, albeit with larger associated uncertainties, compared with the results obtained by mass balance procedures. Possible reasons for this divergence are discussed in the report, without reaching a definitive conclusion as to their origin.The comparison demonstrates that for a structurally complex polar organic compound containing a high water content and presenting a number of additional analytical challenges, the assignment of the mass fraction content property value of the main component can reasonably be achieved with an associated relative standard uncertainty in the assigned value of 0.5%Main textTo reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Occurrence of Antibiotics in an Agricultural Watershed in South-Central Idaho.

The polar organic compound integrative sampler (POCIS) is a tool that has been effectively used to passively sample organic pollutants over long periods in aquatic environments. In this study, POCIS were used to investigate the spatial and temporal occurrence of 21 antibiotics in irrigation return flows and upstream sites of an intensively managed agricultural watershed in south-central Idaho. The antibiotic metabolite, erythromycin-HO, and the antibiotics monensin, oxytetracycline, sulfadimethoxine, sulfamethazine, sulfamethoxazole, trimethoprim, and tylosin were detected at frequencies ranging from 3.1 to 62.5%, with monensin having the highest rate of detection. The fact that monensin was the most frequently detected compound indicates that it is entering return flows in runoff from fields that had received livestock manure or wastewater. Antibiotics (except oxytetracycline, sulfamethazine, and tylosin) were also detected at an upstream site that consisted of diverted Snake River water and is the source of irrigation water for the watershed. Therefore, even cropped soils that are not treated with manure are still receiving low-level antibiotics during irrigation events. This study provides the first set of evidence that surface waters within this agricultural watershed contain antibiotic residues associated with veterinary and human uses.

Assessment of biodegradation potential at a site contaminated by a mixture of BTEX, chlorinated pollutants and pharmaceuticals using passive sampling methods – Case study

The present study describes a pilot remediation test of a co-mingled plume containing BTEX, chlorinated pollutants and pharmaceuticals. Remediation was attempted using a combination of various approaches, including a pump and treat system applying an advanced oxidation process and targeted direct push injections of calcium peroxide. The remediation process was monitored intensively and extensively throughout the pilot test using various conventional and passive sampling methods, including next-generation amplicon sequencing. The results showed that the injection of oxygen-saturated treated water with residual hydrogen peroxide and elevated temperature enhanced the in situ removal of monoaromatics and chlorinated pollutants. In particular, in combination with the injection of calcium peroxide, the conditions facilitated the in situ bacterial biodegradation of the pollutants. The mean groundwater concentration of benzene decreased from 1349μg·L−1 prior to the test to 3μg·L−1 within 3months after the calcium peroxide injections; additionally, monochlorobenzene decreased from 1545μg·L−1 to 36μg·L−1, and toluene decreased from 143μg·L−1 to 2μg·L−1. Furthermore, significant degradation of the contaminants bound to the soil matrix in less permeable zones was observed. Based on a developed 3D model, 90% of toluene and 88% of chlorobenzene bound to the soil were removed during the pilot test, and benzene was removed almost completely. On the other hand, the psychopharmaceuticals were effectively removed by the employed advanced oxidation process only from the treated water, and their concentration in groundwater remained stagnant due to inflow from the surroundings and their absence of in situ degradation. The employment of passive sampling techniques, including passive diffusion bags (PDB) for volatile organic pollutants and their respective transformation products, polar organic compound integrative samplers (POCIS) for the pharmaceuticals and in situ soil microcosms for microbial community analysis, was proven to be suitable for monitoring remediation in saturated zones.

A method to account for the effect of hydrodynamics on polar organic compound uptake by passive samplers.

Mass transfer coefficients of the water boundary layer (kw ) were measured using alabaster dissolution kinetics in a diffusion cell that was operated at stirring rates between 90 min-1 and 600 min-1 , aiming to provide a more robust characterization of the effect of hydrodynamics on the uptake of polar compounds by passive samplers, as compared with characterizations in terms of stirring rates and water flow velocities. The measured kw helped to quantitatively understand calcium sulfate transport through a poly(ethersulfone) membrane and 2 water boundary layers (at both sides of the membrane). Alabaster-based kw value were used to understand atrazine transport in the diffusion cell, allowing the conclusion that atrazine transport in the membrane is via the pore space, rather than via the polymer matrix. The merits of measuring alabaster dissolution rates for passive sampler calibration and application in the field are discussed. The authors propose that passive sampler calibrations be carried out under controlled kw conditions, rather than under controlled stirring rates or flow velocities. This would facilitate the interpretation of passive sampler calibration studies and the translation of laboratory-based water sampling rates to flow conditions that apply in the field. Environ Toxicol Chem 2017;36:1517-1524. © 2016 SETAC.

Passive sampling of pharmaceuticals and personal care products in aquatic environments

Passive sampling is a rapidly developing technology, which is widely used for the monitoring of pollutants in different environments. Passive sampling offers significant advantages over traditional grab sampling. In the present review, the authors summarize the current literature on the methods of passive sampling used in the environmental monitoring of polar or semi-polar compounds in aqueous matrices. Methods of calibrating, design and deployment of samplers are also discussed. A major focus of this review is the use of polar organic compound integrative samplers (POCIS) and their use in sampling and monitoring of pharmaceuticals and personal care products (PCPs) in both equilibrium and non-equilibrium conditions.

Occurrence of pharmaceutical compounds and pesticides in aquatic systems

This paper deals with the detection and quantification of APIs and other priority substances in the Arade River estuary (Portugal) providing the usefulness of Polar Organic Compound Integrative Samplers (POCIS). Thirteen APIs were detected whose variation was site and time dependent. Caffeine was at the highest concentration (804±209ng/L) followed by theophylline (184±44ng/L). Other APIs were analgesic, anticonvulsant, non-steroidal anti-inflammatory drugs, anti-lipidemic, anxiolytic and antidepressants. Twenty pesticides comprising atrazine, diuron, isoproturon, terbutryn and simazine included in the Water Framework Directive priority list were also site and time dependent. Carbendazim occurred at the highest concentration (45±18ng/L at site 1) but atrazine, diuron, isoproturon and simazine levels were below the Environmental Quality Standards. Although the summer impact was unclear, the results highlighted POCIS suitability for profiling these contaminants. This is to our knowledge the first study concerning APIs and pesticides in this area.

Influence of activated carbon porosity and surface oxygen functionalities’ presence on adsorption of acetonitrile as a simple polar volatile organic compound

Based on series of porous carbon models, systematic Monte Carlo studies on the adsorption of acetonitrile (as a simple representative of polar volatile organic compounds) were performed. The influence of porosity and chemical composition of the carbon surface on CH3CN adsorption was studied and it was shown that both the factors influenced the adsorption mechanism. A decrease in the pore size and the introduction of oxygen surface groups led to a rise in adsorption energy and to an increase in the filling of accessible volume in the low-pressure part of the isotherm. However, from a practical point of view, it is easier to increase the adsorption by introducing polar groups on the carbon surface than by modifying the porosity.

Layering on solar cell power and stability

Solar Cells Solar cells made from carbon-based polymers are helpfully flexible. However, there's been a frustrating tradeoff between cell stability and efficiency when converting solar power to electrical power. Page et al. offer a strategy to partially resolve this dilemma by inserting a layer of polar organic compound (a fullerene derivative) between the cathode (the positive pole in the circuit) and the rest of the cell. Aluminum is an efficient cathode material but is prone to oxidative degradation. The easily applied polar layer enables the use of more stable metals, such as silver and copper, for the cathode, while counteracting their tendencies to diminish power conversion efficiency. Science , this issue p. [441][1] [1]: /lookup/doi/10.1126/science.1255826

Fulleropyrrolidine interlayers: tailoring electrodes to raise organic solar cell efficiency.

A major challenge in organic solar cell design is the trade-off between oxidative stability and work function of the metal cathode. We found that in single-junction polymer solar cells, this problem can be surmounted by solution-based incorporation of fulleropyrrolidines with amine (C60-N) or zwitterionic (C60-SB) substituents as cathode-independent buffer layers. Specifically, a thin layer of C60-N reduced the effective work function of Ag, Cu, and Au electrodes to 3.65 electron volts. Power conversion efficiency values exceeding 8.5% were obtained for organic photovoltaics independent of the cathode selection (Al, Ag, Cu, or Au). Such high efficiencies did not require precise control over interlayer thickness, as devices prepared with C60-N and C60-SB layers ranging from 5 to 55 nanometers performed with high efficiency.

Interaction between Kaolin and DMSO: FTIR, XRD , thermodynamic and Nano studies

Intercalation of highly polar organic compound dimethylsulfoxide (DMSO) with kaolinite and the formation of interlamellar complexes has been studied, and characterized by X-ray diffraction (XRD), Fourier transform-infrared spectroscopy (FTIR). Interaction was found to be dependent on the particle size of kaolin raw material. Nature of interaction achieved through the formation of hydrogen bonds between DMSO and both AlOH and Si – O surface of kaolinite. Effect of temperature on equilibrium adsorption of methylene blue (MB) from aqueous solution using kaolin and kaolin – DMSO complexes also studied, the results were analyzed by Langmuir and Freundlich isotherms. Thermodynamic parameters such as ΔG, ΔH and ΔS were calculated. Results suggested that the MB adsorption on kaolin was spontaneous and exothermic process.