Nonionic Substances Research Articles

Sorption Properties of Bentonite-Based Organoclays with Amphoteric and Nonionic Surfactants in Relation to Polycyclic Aromatic Hydrocarbons

Polycyclic aromatic hydrocarbons (PAHs) are a major scientific challenge due to their profound impact on public and environmental health. Therefore, studying ways to detoxify PAHs is important. In this research, the adsorption ability of bentonite modified with five surfactants, including amphoteric (cocoamphodiacetate disodium and sodium cocoiminodipropionate) and nonionic (lauramine oxide, cocamide diethanolamine, and alkylpolyglucoside) substances for the adsorption of high-molecular benzo(a)pyrene and low-molecular naphthalene from the PAH group was studied. The bentonite and bentonite-based organoclays were characterized using X-ray diffraction and Fourier transform infrared spectroscopy. The results showed that the maximum adsorption of benzo(a)pyrene by organoclays increased compared with the initial mineral. The adsorption of benzo(a)pyrene is higher than that of naphthalene. The adsorption process of benzo(a)pyrene by bentonite and organoclays is predominantly monolayer, as it is better described by the Langmuir model (R2 0.77–0.98), while naphthalene is predominantly multilayer, described by the Freundlich model (R2 0.86–0.96). According to the effectiveness of sorption capacities of organoclays—including the degree of sorption, Langmuir and Freundlich constants, the value of maximum adsorption, Gibbs free energy, and the index of favorability of the adsorption process—the most effective modification was found. For the adsorption of benzo(a)pyrene the best was cocoamphodiacetate disodium, and for naphthalene it was sodium cocoiminodipropionate.

Fabrication of carbon-based hydrogel membrane for landfill leachate wastewater treatment

The challenge of effectively managing the discharge of metal ions into aquatic environments, which poses a significant risk to both human health and ecosystems, persists despite the availability of various analytical tools and techniques. There are limitations of existing separation technologies and the inefficacy of hydrogel materials in removing low molecular weight contaminants, such as metal ions, in aqueous solutions. This study added carbon powder to the hydrogel membrane to reduce the low-mechanical strength and drying problems and increase its capacity for adsorbing ionic and non-ionic substances. The study introduced a novel carbon-based aluminium hydroxide hydrogel for wastewater filtration. CG was characterized using various analytical techniques, including examining surface morphology, elemental analysis, surface functional groups, and surface charge. These analytical tools provided a comprehensive understanding of the properties and performance of the CG. The effects of different carbon-based hydrogel (CG) concentrations on water flux and ion rejection were evaluated in a gravity filtration setup. Experiments investigated the influence of different ion concentrations, activated carbon (AC) concentration, centrifugation, water flux, and rejection on removing heavy metals from synthetic and natural wastewater. The pure water flux of the hydrogel membrane was 120 LMH. The results indicated that an AC concentration of 4 g/L in the aqueous solution is optimal for heavy metals removal, with 99.9 % removal for Pb2+ and Cu2+, 84 % rejection for Ca2+, and 85 % rejection for Mg2+ in 10 mg/L of synthetic water. Besides, the 4 g/L AC hydrogel membrane removed 90 % of Ni, Zn, Pb, As, and Cu ions and 53 % of the total organic carbon from leachate wastewater.

Mobility in the context of exposure-based assessment of chemicals for drinking water resourceprotection.

In order to protect European Union (EU) drinking water resources from chemical contamination, criteria for identifying persistent, mobile, and toxic (PMT) chemicals and very persistent and very mobile (vPvM) chemicals under the EU REACH Regulation were proposed by the German Environment Agency (Umweltbundesamt-UBA). Additionally, new hazard classes for PMT and vPvM substances in the revised EU classification, labeling, and packaging (CLP Regulation) are intended. Therefore, a reliable approach in theidentificationof potential drinking water resource contaminants is needed. The scientific basis of the property-based PMT/vPvM criteria, focusing on mobility, which dictates the migration of chemicaldrinking water sources, was evaluated, and a critical analysis of the deviation of sorption metrics from simple behavior was carried out. Based on our evaluation, a Koc may be used for nonionic substances on a screening level only, requiring a higher tier assessment. It is considered inappropriate for hydrophilic and ionizable chemicals, particularly for soils with low organic carbon contents. The nonextractable residue formation is complex and not well understood but remains significant in limiting the mobility of chemicals through soils and sediments. In order to inform the EU commission's work on the introduction of new hazard classes for PMT and vPvM substances into the European legislation, the derivation of a tiered approach is proposed,which utilizes the weight of evidence available, with adoption of appropriate higher tier models commensurate with the nature of the substance and the data available. Integr Environ Assess Manag 2023;19:775-791. © 2022 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

On the importance of nonionic osmotically active substances of the blood for the pathogenesis of severe alcoholic delirium

The main non-ionic osmotically active substances in blood serum are glucose and urea. The aim of the study was to study the changes in the water-osmotic state caused by non-ionic (organic) substances in patients with delirium tremens (DT) and in a state of alcohol withdrawal, and to assess their influence on the blood leukocyte composition and the clinical manifestations of the disease. A total of 747 men were examined in a state of alcohol withdrawal; of these, 450 people had manifestations of severe DT (F10.43), 213 — “classic” DT (F10.4), 84 patients had signs of alcohol withdrawal with somatic and vegetative manifestations (F10.3). To quantitatively describe the composition of leukocytes, an index equal to the neutrophil to lymphocyte ratio (NL-R) was used. We were able to mathematically describe a previously unknown quantitative relationship between the osmolarity level due to non-ionic osmotically active substances in blood serum and the NL-R values. It is expressed by the following formula: G + U = 1 mmol/L (log2 NL-R + 9.5), where G — concentration of glucose in blood serum, mmol/l; U is the concentration of urea in the blood serum, mmol/l; NL-R — neutrophil-lymphocyte index, units; 1 mmol/l — coefficient providing the required dimension of the result; log2 — logarithm with base 2; 9.5 is a constant whose size depends on the selected system of units. It was found that regular changes in blood osmolarity in patients with alcohol withdrawal and DT, both at the stage of initiation of psychosis and during the progression of the disease and the formation of severe DT, occur mainly, and maybe completely, due to non-ionic osmotically active substances. Glucose and urea have their unique role in the formation of homeostasis disorders during the development of the disease in individuals with uncomplicated alcohol withdrawal, as well as DT of varying severity.

Influence Of The Size Of Colloid Nanorized Systems On The Luminescence Intensity Of Eu(III) And Tb(III) Complexes

Optimal conditions for complexation of Tb(III) ions with norfloxacin, keterolac, 2-oxo-4-hydroxyquinoline-3-carboxylic acid amide derivative and Eu(III) with oxytetracycline were established. The dependence of the luminescence intensity (Ilum) of complexes on the acidity of the medium, the type of solvent, the luminescent characteristics of complex compounds were determined, the average lifetime of the excited state of europium and terbium ions in complex compounds in the presence and absence of cationic, anionic and nonionic substances, and the size of colloidal nanoscale systems based on these complexes is established. Analysis of the influence of the type of surfactants on the processes of excitation energy transformation in the complexes of Eu(III), Tb(III) with some drugs was studied by the method of dynamic light scattering. It was found that the luminescence intensity of colloidal nanoscale systems based on Tb(III) and Eu(III) complexes increases in the presence of cationic surfactants(СPC) and nonionic surfactant (Triton X-100), which is associated with a decrease in their size, although other factors may be involved: synergetic effects, displacement of water molecules from the internal coordination sphere of the complex and increasing the rigidity of the complex during coordination with surfactants. Exceptions are Eu – OxTc, Tb-R2, Tb-Nor complexes in the presence of anionic surfactants (SDS), the size of which increases, which can be explained by the formation of triple complexes. The intensity of their luminescence increases, because in these cases there is a displacement of water molecules from the internal coordination sphere of the complex in coordination with SDS.

Milestone Studies on Ion-exclusion Chromatography of Ionic and Nonionic Substances Utilizing Multifunctional Separation Mechanism of Ion-exchange Resins.

Ion-exclusion chromatography (IEC) is categorized as a type of ion chromatography and is recognized as a simple and convenient water quality monitoring technology for a variety of ionic and nonionic substances. This review, mainly focusing on historical milestone studies by various authors, outlines the archives that concern the separation sciences and practical applications obtained from a variety of IEC modes used for water-quality monitoring as follows: (1) early-developed IEC; (2) IEC using enhanced conductivity detection for weak ionic substance; (3) IEC using nonionic substances eluents such as sugars or polyols; (4) vacancy IEC based on a novel separation concept; (5) applications to the water quality monitoring of inorganic ionic-nutrients; (6) simultaneous IEC and cation-exchange chromatography of anions and cations; and (7) the multicomponent IEC combining different separation modes and detection methods with the expansion of applicable fields, such as for food analysis or material evaluations.

Intriguing Clinical and Pharmaceutical Applications of IERs: A Mini Review

Ion exchange resins (IERs) are solid poly-electrolytes which have both sorption and exchange capacity of several organic compounds. They have the power to separate ionic and non-ionic substances with the surrounding medium. The drug materials or substances are adsorbed on resin, which is commonly known as resinate, these features of IERs have useful applications in pharmaceutical formation (i.e., taste masking, stability and solubility enhancement, etc.) and major applications in drug delivery (i.e., oral, nasal, ophthalmic, transdarmal drug delivery). IE principles have been exploited in the investigation of numerous drug industry problems for many years. Synthetic IERs have been extensively employed in pharmacy and medicine, especially for taste masking or controlled release of drugs and have been expansively studied in the development of novel drug delivery systems and other biomedical applications. In this review, the fascinating IERs involving ion exchange processes in pharmaceutical and clinical applications and also their recent advanced uses have been discussed.

Determination of Ionic and Nonionic Perfluoroalkyl Substances (PFASs) in the Surface Water of the Qiantang River, China by Solid-Phase Extraction (SPE) and Ultra-High Performance Liquid Chromatography-Tandem Mass Spectrometry (UHPLC-MS/MS)

An improved analytical method was developed for the simultaneous quantification of ionic and nonionic perfluoroalkyl substances (PFASs) in surface water followed by ultra-high performance liquid chromatography (UHPLC-MS/MS). The conditions for liquid chromatography and mass spectrometry were optimized and several solid phase extraction cartridges and elution solvents were compared. The low detection limits of the analytes ranged from 0.010 to 0.285 ng/L. Reasonable recoveries (76.4–112.3%) were demonstrated at different spiked levels with relative standard deviations lower than 18.9%. The method was applied for the surface water samples collected from different sampling sites in the Qiantang River, China. The results showed that 7 perfluoroalkyl carboxylic acids and 3 perfluroalkane sulfonic acids were detected while perfluorosulfonamide were not present. In addition, the total concentrations of PFASs in middle and downstream of the Qiantang River were higher (154.11–199.28 ng/L) than upstream (9.38–9.80 ng/L), which may be due to presence of the textile and paper industries.

The effects of sunlight on the composition of exopolymeric substances and subsequent aggregate formation during oil spills

Abstract During the Deepwater Horizon oil spill, a large amount of marine oil snow (MOS) was formed in surface waters of the Gulf of Mexico (GOM) that eventually settled to the bottom. MOS consists of a microbially colonized matrix of extracellular polymeric substances (EPS), to which cells, and both ionic (e.g., trace nutrients, Ca 2+ ) and non-ionic (e.g., toxic oil) substances can attach. The secretion of EPS is one of the microbial defense strategies against harmful or stressful environmental situations. In the surface waters, the toxicity of oil can be enhanced by elevated oxidative stress through UV radiation . To test the effects of sunlight on the composition and secretion of EPS and the subsequent aggregation process, we conducted short-term irradiation experiments in three treatments, i.e., control (GOM coastal seawater), water accommodated fraction of oil (WAF), and chemically-enhanced WAF (CEWAF). EPS composition (mainly carbohydrates and proteins) was quantified in the colloidal and aggregate fractions. In addition, bacterial abundance, live/dead cell ratio, particle size distribution , and the ambient hydroxyl radical ( OH) formation rate were measured under these conditions. We found that in the presence of oil, natural sunlight stimulated polysaccharide secretion, coinciding with increased reactive oxygen species (ROS; i.e. OH) production. Moreover, formation of larger sized aggregates (>10 μm) was observed in the irradiated WAF treatments. The results support the hypothesis that sunlight plays an important role in MOS formation during an oil spill.

THE EFFECT OF SURFACTANTS ON THE CHEMILUMINESCENT REACTION OF LUMINOL WITH HYDROGEN PEROXIDE

The luminol-hydrogen peroxide chemiluminescent system is widely used for the creation of diagnostic systems, for chemical analysis, for studying the kinetics and mechanisms of chemical reactions, for the creation of special and emergency light sources, and for monitoring living systems. However, the use of the luminol-hydrogen peroxide chemiluminescent system is limited by the fact that there are almost no ways of managing the reaction. The introduction of organized molecular systems into the luminol-hydrogen peroxide chemiluminescent system can create an additional channel for controlling chemiluminescent reactions. The luminol-hydrogen peroxide system was not previously studied in various classes of hydrocarbon and perfluorinated micellar solutions. This work was the first to study the effect of cationic, anionic and nonionic hydrocarbon surface-active substances (cetyltrimethylammonium bromide, sodium decyl sulfate, sodium dodecyl sulfate, triton X 100) and perfluorinated surface-active substances (FT-135 and FT-248) on the chemiluminescent systems luminol-hydrogen peroxide-potassium hexacyanoferrate(III) and luminol-hydrogen peroxide-copper(II) sulphate. The systems retain the ability to chemiluminescence in the presence of a surfactant. Cationic surfactants lower the intensity of chemiluminescence, and anionic surfactants increase the intensity of chemiluminescence. The introduction of a surfactant into the system allows increasing the range of dependence of the chemiluminescence intensity on the catalyst concentration. Kinetic curves of the growth and decay of chemiluminescence were measured in the systems. The rate constants of the chemiluminescence decay were measured in the framework of the first-order kinetics model.

THE EFFECT OF WATER LUBRICATION WITH ADDITION OF NON-IONIC AND ANIONIC SURFACTANTS ON THE WEAR OF THE FRICTION PAIR WITH A CONCENTRATED CONTACT

In order to minimize losses caused by friction, various technical solutions are applied. Most frequently, however, they are limited to proper lubrication. Two aspects of the problem have to be taken into consideration nowadays: ecology and an economic approach, which involves a possibility of the creation of the cheapest lubrication compositions. Therefore, new lubricants which have a neutral impact on the environment and are characterised by the lowest production costs and the highest effectiveness in the wear of co-operating elements are researched. The main purpose of this paper is an evaluation of the influence of water-based lubrication with an addition of non-ionic and anionic surface-active substances on the wear of a friction pair with a concentrated contact. Laboratory tests were carried out with the use of a T-02 four-ball wear tester and a digital microscope. A series of measurements were conducted in which a tribological connection was lubricated with water and a mixture of water and non-ionic and anionic surfactants of various mass concentrations in reference to water. The conducted research takes into account criteria connected with the minimization of the production costs of lubricating compositions and the minimization of their influence on the environment with a simultaneous limitation of the wear of the co-operating elements. The results obtained in the research enabled an analysis of the influence of the additions of detergents at various concentrations on water lubricating properties, water surface tension, and the volumetric wear of the analysed samples.

Obtaining of Bitumen Emulsions using Nonionic Surface-Active Substances

Background: One of the trends concerning an effective use of large-tonnage and yet scarce binder as bitumen is a considerable introduction of bitumen emulsions in water into the practice of road and civil construction. Methods: The paper presents the experimental data on the research of bituminous emulsions, the physical-chemical properties of an original BND bitumen 60/90 from Zyuzeevsky NBZ and the bitumen residue there of. Results: The resulting emulsions were highly stable and were referred to slowly structured (slowly decomposing) ones, which may be used in the preparation of cold bituminous mineral mixtures of different density used for storage, the strengthening of soils, dust removal from roads. These emulsions had a viscous consistency that may be used for solving the problem of bitumen emulsions application to an inclined surface. Bituminous residues differ by the improvement of a film binder adhesion performance with mineral material (adhesion) without the use of additional adhesion additives. Conclusion: The use of such a component, which also has an emulsifying ability and an adhesion effect, an increased resistance to delamination and coalescence of an emulsion during storage, bitumen saving and the environmental rate.

Thin-layer chromatography in the analysis of biologically active ionic and ionizable compounds

Ionic and ionizable solutes constitute a large group of compounds characterized with biological activity. Chromatographic analysis of these compounds is more difficult when compared to nonionic substances. This review focuses on different approaches used for the separation of basic and acidic substances by means of thin-layer chromatography. Biologically active basic compounds are more often used as prescribed drugs; therefore, chromatographic analysis of these substances was described in more detail when compared to acidic solutes. Direct stimulus to write this review was the 65th anniversary of Prof. Monika Waksmundzka-Hajnos’ birthday. Prof. Hajnos is known for her great contributions to chromatographic analysis of ionic solutes.

PBT borderline chemicals under REACH

The European chemicals legislation REACH (Registration, Evaluation, Authorization and Restriction of Chemicals) defines criteria to identify substances of very high concern (SVHC). Within these, the property combinations ‘persistent, bioaccumulative and toxic’ (PBT) and ‘very persistent and very bioaccumulative’ (vPvB) are of specific priority. In Annex XIII, the determination of SVHC by ‘weight-of-evidence’ is also underlined, e.g. elevated pollutant concentrations in biota ‘compared to levels in their surrounding environment’, which may result from long-range transport potential (LRTP). Nevertheless, LRTP is not included explicitly, although substances may represent an environmental hazard to the intrinsic value of sensitive remote regions as highlighted in the Guidance for the implementation of REACH. Here, it is also recommended to include ‘borderline cases’, i.e. substances where one or more of the P, B and T criteria are not met but an equivalent concern is given by other information, in particular LRTP. We define substances as potential borderline cases, which fail one of the criteria (vP or vB, P or B or T) that have to be evaluated to identify SVHC by less than 10% and are, at the same time, identified to show high LRTP, and apply this definition to prioritize potential SVHC out of the list of 5,306 compounds registered in 2012 under REACH. Eight compounds can be identified as vPvB and less than 2% as PBT compounds out of 1,022 organic, non-ionic substances. In addition, 13 borderline chemicals are contained in the list, which are characterized by LRTP. Three compounds fail one of the vPvB/PBT criteria by less than 10% only and show LRTP which strongly indicates that they should be considered as SVHC. Sensitivity analysis shows a rather stable classification around the arbitrarily fixed 10% value. It is concluded that several LRTP screening methods should be applied to reduce the uncertainty in LRTP determination.

Adsorption kinetic and mechanistic studies for pharmaceutical spherical carbon adsorbents: Comparison of a brand product and two generics

The kinetic and mechanistic profiles of three pharmaceutical spherical carbon adsorbents, Kremezin as the brand product and two generics (Merckmezin and spherical carbon adsorbent “Mylan”), were compared. Five non-ionic active pharmaceutical ingredients with molecular weights of 136.1–424.1Da were used as adsorbates. The results of Boehm titration, the standard method to qualify acidic or basic functional groups on a carbon surface, suggested distinctly different quantitative characteristics of each functional group among the three adsorbents. But those differences do not affect the adsorption to non-ionic adsorbates. The amount of theophylline adsorbed at equilibrium and surface area well correlated, suggesting that adsorptive ability was defined by surface area. In the tested molecular weight range, the order in terms of adsorption kinetics was spherical carbon adsorbent “Mylan”>Kremezin>Merkmezin. The adsorption profile in the equilibrium and kinetic experiments, and the lack of an effect of pH on adsorption quantity suggested that the mechanism of adsorption for non-ionic substances to be Langmuir type monolayer adsorption. Kremezin and spherical carbon adsorbent “Mylan” are more likely to adsorb co-administered drugs than Merckmezin.

The effect of water activity on the sorption and diffusion of water in thermosets based on polyester, vinyl ester, and novolac resins

AbstractIn this work, the transport properties of water in various thermoset resins typically used for fiber‐reinforced plastic process equipment (vinyl ester, novolac, bisphenol‐A‐epoxy‐based polyester, and urethane‐modified vinyl ester) were systematically studied with a focus on the effects of water activity. Sorption and desorption studies were carried out in aqueous solutions (water activity = 0.78–1) with different salts (NaCl, MgCl2, Na2SO4, and KCl) and one nonionic substance (sucrose) within the temperature interval 65–95°C. It was found that the water concentration in thermoset resins with different chemical structures could be predicted from the water activity, regardless of the actual solute (salt or sucrose) in the aqueous solution. The water quasi‐equilibrium concentration decreased with decreasing water activity, whereas the average diffusion coefficient was considered to be independent of water activity in the studied water activity range. A relationship, based on a power law fit, was established describing the water concentration as a function of the water activity and the concentration of pure water. The relationship was independent of resin chemistry and temperature. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers

Physicochemical interactions between drugs and superdisintegrants

Abstract We have evaluated the interactions between superdisintegrants and drugs with different physicochemical characteristics, which may affect the in-vivo absorption e.g. after mucosal administration. The binding of sodium salicylate, naproxen, methyl hydroxybenzoate (methylparaben), ethyl hydroxybenzoate (ethylparaben), propyl hydroxybenzoate (propylparaben), atenolol, alprenolol, diphenhydramine, verapamil, amitriptyline and cetylpyridinium chloride monohydrate (CPC) to different superdisintegrants (sodium starch glycolate (SSG), croscarmellose sodium (CCS) and crospovidone) and one unsubstituted comparator (starch) was studied spectrophotometrically. An indication of the in-vivo effect was obtained by measuring the interactions at physiological salt concentrations. SSG was investigated more thoroughly to obtain release profiles and correlation between binding and ionic strength. The results showed that the main interactions with the anionic hydrogels formed by SSG and CCS were caused by ion exchange, whereas the neutral crospovidone exhibited lipophilic interactions with the non-ionic substances. The effect of increased ionic strength was most pronounced at low salt concentrations and the ion exchange interactions were almost completely eradicated at physiological conditions. The release profile of diphenhydramine was significantly affected by the addition of salt. It was thus concluded that the choice of buffer was of great importance for in-vitro experiments with ionic drugs. At physiological salt concentrations the interactions did not appear to be strong enough to influence the in-vivo bioavailability of any of the drug molecules.

Natural Convection as an Asymmetrical Factor of the Transport Through Porous Membrane

For nonionic substances, which density of solution depends on its concentration, concentration polarization of the membrane in horizontal plane depends not only on diffusion but on the hydrodynamic instabilities at the membrane surfaces also. Such instabilities are the cause of asymmetry of membrane transport in gravitational field. On the basis of results of glucose transport through the Nephrophan membrane in horizontal plane we can state that this asymmetry was observed for the cases with concentration Rayleigh number greater than critical value (R C )crit = 1709.3. The mathematical model based on Kedem–Katchalsky equations and Rayleigh number was presented. On the basis of this model and the dependence of volume flux through the Nephrophan membrane as a function of glucose concentration in the upper (configuration B) and lower (configuration A) chamber of the membrane system, the dependencies of thickness of concentration boundary layer, Rayleigh number, and introduced coefficient of asymmetry as a function of glucose concentration were presented for both configurations. These dependencies show that asymmetry of the membrane transport is observed for glucose concentration higher than 0.015 mol l−1.

Arthrography with Non-ionic Contrast Substances (Optiray 300) in Dogs

Arthrography is an investigation method of the joint space, which is more frequently used in the canine species, which allows routine observations of it and also the diagnosis of pathology localized in the joint head or the synovial membrane. It can be practiced on the dog in joints that have or have not an articular capsule, more frequent in the shoulder (scapula-humerus) and stifle (femur-tibia-patella), and rarely in the elbow (humerus-radius-ulna) or hip joint (coxal-femur), with the purpose of diagnosing the integrity of the articular capsule, of the elements of the articular space and the cul de sac of the synovial membrane [1, 2, 6, 7, 8]. In the professional literature, numerous clinical and radiographic studies have been reported, which demonstrated that arthrography is a highly valuable method in the diagnosis of osteochondritis dissecans of the shoulder joint [3, 4, 5].

The influence of micelle forming process in nonionic surface active substances on diclofenak-sodium release rate from ointments

The influence of the nonionic surface active substances (long-chain fatty alcohols) on the medicinal substances release rate has been studied on the pattern diclofenak-sodium ointments (1%). The increase of the surfactant quantity in the ointment has not been found to lead a direct increase of the diclofenak-sodium release rate. Two surfactant concentrations have been determined provoking the maximum diclofenak-sodium release rate they from the ointment. Liquid crystalline phase has been shown to form when surfactant concentration exceeded the second critical micelleformation concentration, diffusion through the phase being the lowest one.