Mixture Of Organic Compounds Research Articles

Nanodiamonds with SiV colour centres for quantum technologies

Properties of silicon-vacancy (SiV) colour centres in ultra-nanosize diamonds are studied. Nanodiamonds are obtained at a high temperature and pressure, which induced transformations in mixtures of organic and hetero-organic compounds without metal-catalysts. The size distribution of grown nanodiamonds is determined by the methods of transmission electron microscopy and atomic-force microscopy, as well as by using the model of phonon spatial localisation. In addition, Raman spectra of various nanodiamonds and luminescence properties of SiV-centres are investigated.

Cryoprotectants Disrupt Hydrogen-Bond Networks at the Lipid-Water Interface

Cryoprotectant agents (CPAs) are mixtures of small organic compounds used to inhibit ice-crystal growth during cell and tissue freezing and storage, but these compounds can be themselves toxic to cells. Increased membrane permeability, caused by partial disruption of lipid-lipid interactions, combined with dehydration, have been hypothesized to be the main driver of cell toxicity, but the specific interactions between lipids and cryoprotectants are poorly understood. In this study, we investigate the effects of dimethyl sulfoxide (DMSO) on phosphatidylcholine bilayers. We have measured ultrafast two-dimensional infrared (2D IR) spectra of the ester carbonyl vibrations to directly probe the interfacial hydrogen bond networks. Our measurements directly quantify the picosecond hydrogen bond lifetimes at the ester carbonyl positions. Spectra are interpreted at an atomistic level using molecular dynamics simulations, which are in semi-quantitative agreement with experiment. Our results show that biologically relevant cryoprotectant concentrations (<20 mol%), partially dehydrate the interface, but surprisingly, hydrogen-bond lifetimes are non-monotonic with increasing concentration: 1. Low DMSO concentrations (<10%) severely disrupt the otherwise ice-like interfacial hydrogen bond networks, without altering the lipid-lipid interactions, leading to faster overall hydrogen bond dynamics at the ester carbonyls. 2. Above >10 mol%, dynamics become slower as a result of dehydration, more rigid H-bond conformations, trapped water, and stronger headgroup-headgroup interactions. Together, these results provide an atomistic foundation for understanding the complex effects of cryoprotectants on lipid membranes, showing that different effects dictate the properties of membranes within various cryoprotectant concentration regimes.

Life in The Context of Order and Complexity.

It is generally accepted that life requires structural complexity. However, a chaotic mixture of organic compounds like the one formed by extensive reaction sequences over time may be extremely complex, but could just represent a static asphalt-like dead end situation. Likewise, it is accepted that life requires a certain degree of structural order. However, even extremely ordered structures like mineral crystals show no tendency to be alive. So neither complexity nor order alone can characterize a living organism. In order to come close to life, and in order for life to develop to higher organisms, both conditions have to be fulfilled and advanced simultaneously. Only a combination of the two requirements, complexity and structural order, can mark the difference between living and dead matter. It is essential for the development of prebiotic chemistry into life and characterizes the course and the result of Darwinian evolution. For this reason, it is worthwhile to define complexity and order as an essential pair of characteristics of life and to use them as fundamental parameters to evaluate early steps in prebiotic development. A combination of high order and high complexity also represents a universal type of biosignature which could be used to identify unknown forms of life or remnants thereof.

Micro- and Nanoplastics in Alpine Snow: A New Method for Chemical Identification and (Semi)Quantification in the Nanogram Range.

We present a new method for chemical characterization of micro- and nanoplastics based on thermal desorption–proton transfer reaction–mass spectrometry. The detection limit for polystyrene (PS) obtained is <1 ng of the compound present in a sample, which results in 100 times better sensitivity than those of previously reported by other methods. This allows us to use small volumes of samples (1 mL) and to carry out experiments without a preconcentration step. Unique features in the high-resolution mass spectrum of different plastic polymers make this approach suitable for fingerprinting, even when the samples contain mixtures of other organic compounds. Accordingly, we got a positive fingerprint of PS when just 10 ng of the polymer was present within the dissolved organic matter of snow. Multiple types of microplastics (polyethylene terephthalate (PET), polyvinyl chloride, and polypropylene carbonate), were identified in a snowpit from the Austrian Alps; however, only PET was detected in the nanometer range for both snowpit and surface snow samples. This is in accordance with other publications showing that the dominant form of airborne microplastics is PET fibers. The presence of nanoplastics in high-altitude snow indicates airborne transport of plastic pollution with environmental and health consequences yet to be understood.

Coadsorption of gaseous xylene, ethyl acetate and water onto porous biomass carbon foam pellets derived from liquefied Vallisneria natans waste

AbstractBACKGROUNDOnly a few studies have focused on the purification of waste gas containing a mixture of volatile organic compounds (VOCs) with engineered biochar. The adsorption behaviors of gaseous xylene and ethyl acetate (EA) individually and in binary mixture onto porous biomass carbon foam pellets (BCFPs) were studied by static headspace gas chromatography.RESULTSThe removal efficiency nearly reached 100% for 17.32 mg L−1 xylene and 18.02 mg L−1 EA within 120 min at a BCFP dosage of 0.2 g L−1, a temperature of 40 °C and a relative humidity of 30%. The adsorption behavior followed the pseudo‐second‐order kinetic model for single and binary mixtures of xylene and EA. The coexistence of xylene had considerable influence on the adsorption performance of EA, whereas the coexistence of EA exhibited minimal effect on the adsorption performance of xylene. The monolayer adsorption capacities of sole xylene and EA were 250.63 and 206.61 mg g−1 respectively. The total adsorption capacity reached 322.36 mg g−1 for the binary mixture, but the adsorption capacity for sole xylene and EA decreased because of competitive adsorption. The adsorption process was spontaneous and endothermic. Pore filling was involved in the adsorption of xylene and EA onto BCFPs. Meanwhile, xylene adsorption was involved in the hydrophobic interaction and π–π electron dispersion interaction.CONCLUSIONBCFPs are an effective adsorbent for VOC adsorptive removal from waste gas. Competitive adsorption between xylene and EA on BCFPs was determined. Results indicated that the physicochemical properties of VOCs had an effect on the adsorption performance. © 2019 Society of Chemical Industry

Bezpieczeństwo stosowania olejków eterycznych

Currently, many herbal substances are used in everyday life products and in many industry such as food, cosmetics and others. Essential oils are mixtures of volatile organic compounds separated from plants or parts of them. They are characterized by an intense fragrance, but they have a diverse composition. Depending on the source, there are one or several dominant components. History acquisition of essential oils dates back to ancient times. Due to the unique fragrance qualities, the oils accompany humanity all the time. More perfect methods of analysis of the composition of essential oils used in cosmetics, food (spices) and aromatherapy, prompts us to consider the safety of their use. In addition to health-promoting substances, oils can also contain many organic compounds with an allergic or even toxic effect. Getting to know the essential oils composition and thorough acquaintance of consumers with possible risks of using essential oils is currently a priority for the producers of essential oils.

Insights into pyrolysis of waste tire in fixed bed reactor: Thermal behavior

This study examines the thermal behavior of pyrolysis products of waste tire. The pyrolysis of solid waste tire was conducted under N2 atmosphere in a lab-scale fixed bed reactor. Three different factors were investigated, which were the operating pyrolysis temperature (300, 400, 500, 600 and 700 °C), particle size (80, 40 and 18 mesh size of particles) and carrier gas flow rate (1 and 5 L/min). The optimized liquid product yield was obtained at a pyrolysis temperature of 500 °C for a feedstock of 80 mesh size waste tyre, with a carrier gas flow rate of 5 L/m. The waste tire pyrolysis oil was then characterized via fuel properties determination, elemental, FT-IR and GC-MS analysis. The fuel properties of the tire pyrolysis oil encourage the product as a potential replacement of conventional liquid fuel. The analytical results of the optimized pyrolysis oil showed that the liquid product consists of the complex mixture of C5-C16 organic compounds, with high contents of light hydrocarbon benzene, toluene, xylene and limonene. The present research is a promising approach for an alternate, renewable energy and better environment in the future.

О возможностях многомерной эквидистантной абсорбционной спектроскопии в широком диапазоне частот в исследованиях фракций термической разгонки нефти

The features and possibilities of absorption molecular spectroscopy of complex mixtures of organic compounds by the instance of oil thermal distillation fractions are studied. The problem of studying the spectra of oil fractions as a single object of complex molecular composition was directly solved (i.e. without studing of molecular composition). Thereby multidimensional equidistant spectra were studied in a wide spectral range. Measurement conditions: frequency range from 500 to 1500 cm-1, spectral resolution 1 cm-1, frequency increment 0.5 cm-1, Objects under investigation - 33 fractions of thermal oil distillation. Results processing of spectroscopic measurements was carried out using methods of multifactor mathematical statistics. The efficiency of using absorption molecular spectroscopy in the far infrared region in the study and control of the optical characteristics (absorption spectra) of oil thermal distillation fractions is shown.

Natural Organic Matter Removal in the Context of the Performance of Drinking Water Treatment Processes—Technical Notes

Natural organic matter (NOM) is a very complicated mixture of organic compounds and is detected in all groundwater and surface waters. Besides NOM has a direct effect on health, it touches the performance of drinking water treatment processes (DWTPs) and so the safety of potable water. NOM may also disturb consumer satisfaction since it could participate in undesirable colors, tastes, and odors in potable water. This work aims to provide an insight into the effects of NOM on the global quality of drinking water, comprising its possible impacts on DWTPs and soon the safety of drinking water. It outlines the parameters that touch the level and property of NOM and examines the indexes to adopt when suggesting a NOM control strategy. Water source becomes highly polluted by organic compounds at a level that chemical oxygen demand is presently used to characterize surface water and biological treatment is suggested as a process for NOM removal in the DWTPs. Such behavior was not thinkable thirty years ago. The coagulation process remains importantly influenced by practical variables such as mixing conditions and pH control. Employing membrane processes instead of singular chemical oxidation and coagulation should be more promoted as water supplies become highly polluted in organic compounds.

Characterization and photocatalytic activity of Ag/Mn3O4/graphene composites under visible light irradiation for organic dyes degradation

Ag/Mn3O4 composites were synthesized with various concentrations of graphene using a sol–gel method followed by hydrothermal synthesis. The as-synthesized Ag/Mn3O4/graphene composites were characterized by X-ray diffraction, transmission electron microscopy, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, ultraviolet-visible diffuse reflectance spectroscopy (DRS), Raman spectroscopy, and nitrogen adsorption/desorption isotherm measurements. The photocatalytic performance of the Ag/Mn3O4/graphene composites was tested in organic dye pollutants in pure water as well as in complex mixtures of organic compounds. Therefore, the degradation of organic dyes was also evaluated in the presence of organic acid as common substances in natural water. The characterization results revealed that the Mn3O4 nanoparticles exhibited an excellent stability and crystalline structure and were successfully connected with Ag nanoparticles and graphene. In the presence of organic acid, the degradation of organic dye increases in comparison with the dye degradation in the absence of organic acid. The strength of the synergic effect between photocatalysis and the presence of organic acids was not significantly related to the structure of the organic acid. The effectiveness in increasing the photocatalytic degradation of the organic dyes was as follows: ascorbic acid > oxalic acid > citric acid > formic acid > ethylenediaminetetraacetic acid > acetic acid > no acid > EDTA + ascorbic acid. The leached Mn and Ag species were found to be indirectly proportional to the photocatalytic performance trend. The highest concentrations of leached species were observed when ascorbic acid was present in the solution.

Comprehensive analysis of peptides and low molecular weight components of the giant ant Dinoponera quadriceps venom.

Ants (Hymenoptera, Apocrita, Aculeata, Formicoidea) comprise a well-succeeded group of animals. Like bees and wasps, ants are mostly venomous, having a sting system to deliver a mixture of bioactive organic compounds and peptides. The predatory giant ant Dinoponera quadriceps belongs to the subfamily Ponerinae that include one of the largest known ant species in the world. In the present study, low molecular weight compounds and peptides were identified by on-line peptide mass fingerprint. These include neuroactive biogenic amines (histamine, tyramine, and dopamine), monoamine alkaloid (phenethylamine), free amino acids (e.g., glutamic acid and proline), free thymidine and cytosine. To the best of our knowledge most of these components are described for the first time in an ant venom. Multifunctional dinoponeratoxin peptides variants (pilosulin- and ponericin-like peptides) were characterized that possess antimicrobial, hemolytic, and histamine-releasing properties. These venom components, particularly peptides, might synergistically contribute to the overall venom activity and toxicity, for immobilizing live prey, and defending D. quadriceps against aggressors, predators and potential microbial infection.

Finding possible pharmacological effects of identified organic compounds in medicinal waters (BTEX and phenolic compounds)

Medicinal thermal waters consist of a mixture of different organic and inorganic compounds. Traditionally, these waters are only characterized and classified by their inorganic composition; however, the bioavailability of the majority of these inorganic compounds is limited. Many authors investigate the organic fractions of thermal waters. These authors propose that these compounds have a potential effect on health. To elucidate the underlying mechanisms, it is crucial to know the composition of the organic fractions. The absorption of these compounds on intact skin or mucosa is notable. Some of them have local anaesthetic effect or affect receptors in the central nervous system. In the knowledge of the chemical composition, we are able to estimate the possible pharmacological effect or might be able to assess possible toxicity risks. In the present article, we aim to review possible health effects of two of the identified organic fractions: benzene and alkylbenzenes and phenolic compounds that might correlate with the therapeutic effect on rheumatological or other diseases.

An Efficient Method Development for Extraction of Faecal Volatile Organic Compounds for GC-MS Analysis

Human biological excretions (faeces, urine, breath sweat etc.) contain a complex mixture of volatile organic compounds (VOCs), which are produced as a by-product of metabolic processes within the body..

Gas chromatography-mass spectrometric studies of volatile emissions from plants for the assessment of the effectiveness and chemical safety of the implementation of environment improving phytotechnologies

The chromato-mass-spectrometric studies of volatile emissions of fresh-cut roses have revealed the persistence of wide range of organic compounds. The most large content was consist of terpene hydrocarbons. The contribution of oxygen-containing components (alcohols, ethers, aldehydes and ketones) varied in wide ranges in dependence on the content of the feeding solution. The significant part of plants ’ volatiles has no hygienic norm. Among the substances released into the air space ofpremises with volatile emissions ofplants, a significant part has not hygienic standards. Purposeful change in composition of the mixture of volatile organic compounds released by the plants, in the combination with chemical-analytical control of the content of these substances by gas chromatography-mass spectrometry in terms of ecological and hygienic aspects may be useful in the development, use and determination of the optimal conditions of the implementation of environment improving phytotechnologies and evaluation of the efficacy and safety of their impact on public health.

Hydrogen production in acoustoplasma discharge in a liquid-phase medium flow

In the paper, plasma discharge in a liquid flow at high pressure for use in producing hydrogen gas has been carried out. Methods and equipment for plasma discharge excitation in a liquid medium flow have been developed by the authors. The liquid flow has been directed at excess pressure to the hydrodynamic radiator located at the reactor inlet where an ultrasonic two-phase vapor-liquid flow has occurred at lower pressure due to the pressure difference and decrease in the flow enthalpy. Electric field which intensity exceeds the breakdown threshold of this two-phase medium is generated between electrodes located in the reactor by an external power supply, thus resulting in excitation of the low-temperature quasi-steady plasma glow discharge. Theoretical estimation of the parameters of such discharge has been carried out by the authors. It is shown in the paper that low temperature plasma initiated under the conditions of a liquid-phase medium flow in the discharge gap between electrodes could effectively split hydrogen-containing molecules of organic compounds in a liquid with formation of gaseous products having hydrogen content of more than 90%. In addition, theoretical calculations of the discharge voltage and current which are in good agreement with the experimental results have been carried out in the process simulation. With a mixture of oxygen-containing organic compounds as a raw material, the output capacity of the 50 mL reaction system used in experiments has been around 1.5 l of hydrogen per minute. Decomposition of those compounds in plasma may also result in formation of some solid-phase products, such as carbon nanoparticles and nanoparticles of the discharge electrode oxide materials.

Archaeal nitrification is constrained by copper complexation with organic matter in municipal wastewater treatment plants

Consistent with the observation that ammonia-oxidizing bacteria (AOB) outnumber ammonia-oxidizing archaea (AOA) in many eutrophic ecosystems globally, AOB typically dominate activated sludge aeration basins from municipal wastewater treatment plants (WWTPs). In this study, we demonstrate that the growth of AOA strains inoculated into sterile-filtered wastewater was inhibited significantly, in contrast to uninhibited growth of a reference AOB strain. In order to identify possible mechanisms underlying AOA-specific inhibition, we show that complex mixtures of organic compounds, such as yeast extract, were highly inhibitory to all AOA strains but not to the AOB strain. By testing individual organic compounds, we reveal strong inhibitory effects of organic compounds with high metal complexation potentials implying that the inhibitory mechanism for AOA can be explained by the reduced bioavailability of an essential metal. Our results further demonstrate that the inhibitory effect on AOA can be alleviated by copper supplementation, which we observed for pure AOA cultures in a defined medium and for AOA inoculated into nitrifying sludge. Our study offers a novel mechanistic explanation for the relatively low abundance of AOA in most WWTPs and provides a basis for modulating the composition of nitrifying communities in both engineered systems and naturally occurring environments.

The influence of water content in rice husk bio-oil on the rheological properties of coal bio-oil slurries

Bio-oil from biomass pyrolysis is a mixture of water and organic compounds, which can be used to prepare coal bio-oil slurry (CBS) by blending with coal. The water content in bio-oil has significant effect on the properties of CBS. 57 CBS samples with Shenmu coal concentration of 31–40 wt% and water content in rice husk bio-oil from 27.40 to 48.71 wt% were prepared. The rheology, thixotropy, characteristic viscosity, maximum solid concentration and static stability of the samples were tested. The results showed that the samples could be divided into two groups based on its rheological behavior: strong pseudoplastic and weak pseudoplastic CBS. During storage, all strong pseudoplastic samples were unstable but most of weak pseudoplastic samples were stable. With the increase of water content in bio-oil, CBS behavior changed from weak pseudoplastic to strong pseudoplastic and the transition occurred in the water content of about 45 wt%. Strong pseudoplastic CBS usually showed larger yield stress and thixotropic loop area compared with weak pseudoplastic ones. For all CBS samples, there was a water content in bio-oil where the characteristic viscosity of CBS was the minimum, and its value decreased with the increase in coal concentration.

White Light Emission from a Simple Mixture of Fluorescent Organic Compounds

Three fluorescent organic compounds—furocoumarin (FC), dansyl aniline (DA), and 7-hydroxycoumarin-3-carboxylic acid (CC)—are mixed to produce almost pure white light emission (WLE). This novel mixture is immobilised in silica aerogel and applied as a coating to a UV LED to demonstrate its applicability as a low-cost, organic coating for WLE via simultaneous emission. In ethanol solution and when immobilised in silica aerogel, the mixture exhibits a Commission Internationale d’Eclairage (CIE) chromaticity index of (0.27, 0.33). It was observed that a broadband and simultaneous emission involving coumarin carboxylic acid, furocoumarin and dansyl aniline played a vital role in obtaining a CIE index close to that of pure white light.

The effect of extraction of labile organic fractions on surface properties of pyrochars

The changes in the properties of pyrochars and the possibility of their use as soil meliorants were evaluated. Pyrochars obtained from linden residues at fixed pyrolysis temperatures of 250°C, 450°C and 650°C and under isothermal conditions in the temperature range from 450°C to 650°C have been studied. Their labile fractions of organic matter extracted with Na4P2O7-NaOH solution and hot water was investigated by UV-VIS spectrometry and after extraction cation exchange capacity of pyrochars was characterized. For the qualitative characteristics of the selected fractions, ratio of the absorption of a colored solution of organic matter at λ = 254 nm to the content of organic carbon was calculated. It was concluded, that the pool of water-soluble and alkaline-soluble organic matter of pyrochars is a mixture of organic compounds of uncertain qualitative composition, whose properties are determined by the pyrolysis temperature. Extraction of this water-soluble and alkaline-soluble organic matter leads to a change in cation exchange capacity of pyrochars.

Anaerobic digestion disposal of sewage sludge pyrolysis liquid in cow dung matrix and the enhancing effect of sewage sludge char

Abstract Sewage sludge pyrolysis liquid (SSPL) is a mixture of various toxic organic compounds and moisture, its disposal or valorization are crucial for the sustainability of any pyrolysis plant of sewage sludge (SS). As SSPL showed strong inhibition on anaerobic digestion (AD), in order to fulfill its clean disposal, the study investigates its AD in cow dung matrix under thermophilic condition with sewage sludge char (SSC) addition. Three SSCs produced at different temperatures and two biochars were added into the AD system for comparison. Batch experiments (55 °C, 26 days) reveal that addition of SSCs/biochars could increase cumulative methane yield by 57.5–128.7%/120.7–133.7% compared with the group without char addition. Among three SSCs, the one produced at 550 °C (550SSC) shows the best effect and has similar promotion effects to those of conventional biochars. The mechanism involved is explained by the following facts: SSCs/biochars addition alleviated microbial inhibition effect of SSPL by adsorbing the toxic organic compounds in the liquid at the early stage, hosting microbes to grow, improving the reaction rate and stabilizing the pH of AD system at around 8, finally helping to obtain an earlier occurrence of daily methane yield peak and contributing to higher methane yields. The rich trace elements contained in SSCs, especially in 550SSC, help to promote the growth of microbes and contribute to the decomposition of toxic organic compounds. GC-MS analyses of digestates reveal that SSPL can be well degraded with help of SSCs/biochars addition after AD process. The obtained results suggest that AD of SSPL in cow dung matrix with 550SSC addition is a reliable and economy alternative for its treatment and valorization.