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1.
Chemosphere ; 286(Pt 2): 131611, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34333183

RESUMO

Finding an efficient and economical method to remediate oil spills on water is a priority worldwide. In this article, we propose a solution to this problem using polystyrene magnetic nanocomposite blends composed of polystyrene chains grafted on the surface of silica coated on iron oxide nanoparticles and polystyrene. The hydrophobic and oleophilic magnetic polymer nanocomposite collected oil from the water surface quickly and efficiently. However, when the magnetic polymer nanocomposite was blended with polystyrene, the resulting material also absorbed oil efficiently from the water surface. The blending technique made it easier to prepare the absorbent and dramatically decreased its cost. These new absorbents absorbed oil up to 5 times their own weight in only 5 minutes. The excellent hydrophobicity, low density, and easy magnetic separation makes these new absorbents a promising alternative to recover oil from spilled in fresh and marine water.


Assuntos
Nanocompostos , Poluição por Petróleo , Fenômenos Magnéticos , Óleos , Poliestirenos
2.
Food Chem ; 372: 131258, 2022 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-34627086

RESUMO

Microwave-mediated immiscible binary solvent extraction (MIBSE) was applied to simultaneously extract oil and epigoitrin from Orychophragmus violaceus seeds. The upper phase of n-hexane was used to obtain oil, and the lower phase of ethanol solution was used to obtain epigoitrin. Factors potentially affecting the yields of oil and epigoitrin were systematically investigated. The optimum conditions were an ethanol volume fraction of 65%, liquid-solid ratio of lower-phase of 20 mL/g, liquid-solid ratio of upper-phase of 12 mL/g, microwave irradiation power of 393 W, and microwave irradiation time of 29 min. The actual yields of oil and epigoitrin were 34.08% ± 1.38% and 11.86 ± 0.47 mg/g, respectively. GC-MS analysis illustrated that the seed oils obtained by MIBSE and Soxhlet extraction exhibited similar fatty acid compositions. The separated epigoitrin was determined by HPLC analyses, which obtained a purity of 91.25% ± 3.83%, follwed by NMR determinations.


Assuntos
Micro-Ondas , Sementes , Óleos , Oxazolidinonas , Óleos Vegetais , Solventes
3.
Food Chem ; 372: 131275, 2022 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-34638058

RESUMO

Sunflower protein isolate obtained from industrially de-oiled press cake was treated with non-thermal microwave, aiming to investigate how structure and emulsifying properties were affected. Our results indicated that the content of polar amino acids was decreased and solubility and surface hydrophobicity were altered upon exposure to non-thermal microwave. Higher solubility and surface hydrophobicity of the samples treated with defrost mode and also 350 W were accompanied by a smaller size and lower uniformity of the oil droplets compared to the control and other samples. Non-thermal microwave treatment improved the emulsion stability by 1.43 times and defrost mode treated sample had the lowest stability index after 120 min. Interfacial dilatational rheology measurements revealed that 70 and 350 W treated samples created higher elastic, less stretchable solid-like layer at the O/W interface in comparison with defrost mode treated and control samples. Consequently, non-thermal microwave treatment could be considered as a promising simple, fast, and "green" protein modification technique.


Assuntos
Helianthus , Emulsificantes , Emulsões , Interações Hidrofóbicas e Hidrofílicas , Óleos , Reologia , Solubilidade , Água
4.
Food Chem ; 372: 131357, 2022 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-34655833

RESUMO

Oleogels were prepared by the cryogel-templated method from porous cryogels, which were co-structured using hydroxypropyl-methylcellulose and structural enhancers (such as flaxseed gum, κ-carrageenan, carboxymethyl-cellulose, arabic gum, and guar gum). The hardness, network density, pore size, pore volume, and SEM micrographs of cryogels showed that κ-carrageenan and flaxseed gum could keep the integrity of aqueous foams during freeze-drying and endow cryogels with the high hardness and content to hold oils (>98%). Oil absorption curves indicated that flaxseed gum and guar gum-enhanced cryogels provided the fastest oil absorption rate due to bigger pores. The absorption model was fitted well with all experimental data. Physical and mechanical properties of cryogels were positively related to the rheological property and oil bonding capacity of oleogels. κ-carrageenan and flaxseed gum were more suitable as structural enhancers to improve hydroxypropyl-methylcellulose-based cryogels for preparing oleogels to replace plastic fats in foods.


Assuntos
Criogéis , Água , Óleos , Compostos Orgânicos , Polissacarídeos
5.
Food Chem ; 371: 131384, 2022 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-34808777

RESUMO

In-package cold plasma (ICP) pretreatment is an emerging non-thermal food processing methods. In the current study, ICP on the formation of polycyclic aromatic hydrocarbons (PAHs) in grilled beef steaks with different oils and fats was evaluated, the influence of prolonged storage periods (1 d, 2 d) of raw meat after ICP pretreatment on the PAH inhibitory effect was investigated. The results showed that sunflower seed oil had an inhibitory effect on PAH formation; the groups with ICP pretreatment showed a significant decrease in PAH content (p < 0.05) according to the UHPLC results, inhibitory rates were dependent on the original contents in each group without ICP pretreatment, ranging from 35% to 96%. The optimal condition was grilling immediately after ICP pretreatment, and the results indicated that the nonpolar radical scavenging activity (RSA) of ungrilled meat was negatively correlated with PAH8 contents according the DPPH assay, while ICP pretreatment enhanced the RSAoil of raw meat.


Assuntos
Gases em Plasma , Hidrocarbonetos Policíclicos Aromáticos , Animais , Bovinos , Carvão Vegetal , Culinária , Óleos , Hidrocarbonetos Policíclicos Aromáticos/análise
6.
Chemosphere ; 286(Pt 1): 131520, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34298294

RESUMO

The remediation of oil spills and treatment of oily wastewater remains challenging to cope with nowadays. This has caused a surge in demand on adsorbent materials with multi-functionalities to effectively separate oils and nonpolar solvents from water. A superhydrophobic composite aerogel prepared from industrial waste-derived leached carbon black waste (LCBW) and polyvinyl alcohol (PVA) was developed in this work via conventional freeze-casting followed by surface coating. The composite aerogel was ultralight and porous with porosity >85% and tunable density ranging between 0.015 and 0.065 g/cm3. It was found that the embedded LCBW in the PVA network is crucial to impart superhydrophobicity and superoleophilicity to the aerogel as it enhances the surface roughness. Wettability test showed that composite aerogel prepared from 0.5 wt% PVA at PVA/LCBW ratio of 1 exhibited the highest water contact angle (156.7 ± 2.9°). LCBW also improved the thermal stability of the composite aerogel. With its superior selectivity, PVA/LCBW aerogel was used as selective adsorbent for a variety of oils and organic solvents. The adsorption test showed that the composite aerogel exhibited an adsorption capacity up to 35 times its original weight and could be reused repeatedly and easily recovered through a simple drying method.


Assuntos
Álcool de Polivinil , Água , Géis , Óleos , Óleos Vegetais , Fuligem , Molhabilidade
7.
Chemosphere ; 287(Pt 3): 132254, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34583296

RESUMO

Herein, we demonstrated a facile method for the fabrication of magnetic and superhydrophobic polyurethane sponge with water contact angle of 159° as an adsorbent for cleanup the marine oil spill pollution. For this aim, a polyurethane sponge was coated with carbon black (CB), hexagonal boron nitride (h-BN)@Fe3O4, and acrylic resin and then characterized by different techniques. Owing to the chemical and thermal stability of h-BN and CB, the modified sponge was stable under corrosive conditions (pH = 1-14 and salt solutions) and at different temperatures (-12 °C-105 °C). In addition to common oils and organic solvents, we also used the real spilled oils containing monoaromatics and polyaromatics in the water surfaces of the Persian Gulf for investigation of adsorption efficiency of sponge in a real condition. The oil adsorption capacity of this sponge was in the range of 64-176 g g-1. Also, this adsorbent can separate high amount of oil or organic solvents up to 66,400 times of its own weight from the oil-water mixture in a continuous separation. The results confirm that modified sponge can be used more than 20 times for oil spill cleanup without considerable reduction of its adsorption capacity. Consequently, the modified sponge is a promising candidate material for use in a real oil-water separation process.


Assuntos
Poluição por Petróleo , Interações Hidrofóbicas e Hidrofílicas , Fenômenos Magnéticos , Óleos , Poluição por Petróleo/análise , Poliuretanos
8.
J Colloid Interface Sci ; 607(Pt 2): 1741-1753, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34598031

RESUMO

HYPOTHESIS: A unique adhesion-shielding (AS)-based method could be used to manufacture magnetic Janus nanoparticles (IM-JNPs) of promising interfacial activities, asymmetric surface wettability, and great performance on deoiling from oily wastewater under the external magnetic field. EXPERIMENTS: The IM-JNPs were characterized using scanning electron microscope (SEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and Fourier-transform infrared spectroscopy (FTIR). The interfacial properties of IM-JNPs were investigated by the measurements of interfacial pressure-area isotherms (π-A), oil-water interfacial tension, and the related crumpling ratio. The Langmuir-Blodgett (L-B) technique was used to determine the asymmetric surface wettability of the IM-JNPs. The performance and recyclability of IM-JNPs for treating oily wastewater were also investigated. FINDINGS: Using the proposed AS-based method, 17.9 g IM-JNPs were synthesized at a time and exhibited excellent interfacial properties, as indicated by decreasing oil-water interfacial tension from 38 to 27 mN/m. The crumpling behavior of the oil droplet further demonstrated the irreversible deposition of IM-JNPs at the oil droplet surfaces. The L-B technique and water contact angle measurement confirmed the asymmetric surface wettability of the IM-JNPs. The IM-JNPs were applied to successful removal of > 90% emulsified oil droplets from the household-produced oily wastewater under the external magnetic field while realizing facile recyclability and regeneration.


Assuntos
Nanopartículas Multifuncionais , Fenômenos Magnéticos , Óleos , Tensão Superficial , Molhabilidade
9.
Food Chem ; 367: 130750, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34390909

RESUMO

A novel HPLC-based method for direct separation of trioleoylglycerol (TOG), a major component in high-oleic oils, and its seven hydrolysis products (i.e., oleic acid, monooleoylglycerol (MOG) and dioleoylglycerol (DOG) isomers) was established using a chiral stationary phase column, Chiralpak IA. Within 20 min, all species including enantiomeric MOG (1-sn-MOG and 3-sn-MOG) and DOG (1,2-sn-DOG and 2,3-sn-DOG) were baseline-resolved with resolution factors over 1.5 between adjacent peaks. The established method was used for investigating the integral stereoselectivity, which is the selectivity concerning all hydrolysis steps, of lipase from Pseudomonas fluorescens (PFL) with TOG as substrate. The time-course of DOGs and MOGs indicated that PFL had selectivity for TOG hydrolysis in the order of sn-1, sn-2, and sn-3 position, while it preferred to hydrolyze 2,3-sn-DOG over 1,2-sn-DOG. Being rapid and accurate to evaluate integral stereoselectivity, this method could promote the development and application of lipases with target stereochemistry in the food industry.


Assuntos
Lipase , Óleos , Catálise , Cromatografia Líquida de Alta Pressão , Hidrólise
10.
J Hazard Mater ; 421: 126788, 2022 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-34364204

RESUMO

Development of efficient absorbent materials for oil spillage clean-up and environmental pollution remediation is highly desired but remains a challenge. In this work, superhydrophobic/superoleophilic polysulfone based ZIF-7 composite (SPZ) foams were fabricated via chemical modification of polysulfone and integrating with hydrophobic coin-shaped ZIF-7 particles. The synergistic approaches provided the SPZ foams with high porosity, low density and superhydrophobic/superoleophilic features (θwater=162.3°, θoil=0°) and outstanding self-cleaning property. The as-prepared SPZ foams exhibited highly selective absorption capacity (up to 3800 wt%) for various kinds of oils and organic solvents. Furthermore, the SPZ foams still maintained 95.2% of its pristine absorption capacity and the θwater remained at 143.6° after ten absorption/distillation cycles. The SPZ foam showed outstanding separation ability towards different types of emulsions with separation efficiency all above 97%. The high oil/water separation efficiency and robust reusability made the SPZ foams promising absorbent in dealing with practical oil spills.


Assuntos
Poluição por Petróleo , Água , Interações Hidrofóbicas e Hidrofílicas , Óleos , Polímeros , Sulfonas
11.
J Environ Manage ; 301: 113863, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34610558

RESUMO

This study presents the thermo-chemical conversion by means of pyrolysis as a route to valorise end of life tyres (ELTs) in a sustainable manner whilst targeting produced pyrolysis oil (pyro-oil) to replace conventional fossil fuels. The work presented here compares the results of pyro-oil extracted from the pyrolysis of three tyre grades, namely fresh (new) tyres, car and lorry truck ELTs; and investigates the pyro-oil extracted for fuel properties and common fuel hydrocarbon range. A fixed bed reactor system was used to conduct the experimental runs between 500 and 800 °C. The results show that fresh tyres and car ELTs yield some 45% of pyro-oil at an average reactor bed temperature equal to 600 °C which promotes evolution of liquid hydrocarbons via primary route of tyres cracking, hence pyro-oil production to a maximum. Furthermore, and at a similar operating temperature; the diesel range hydrocarbons (C10-C19) were around 66% of the total fuel like chromatograph studied for the pyrolysis oils. The work in this study and based on properties of fuel investigated point towards blending the oil extracted with conventional fuels that could result in lowering dependency on fossil based ones. Further upgrading is also possible whereby desulphurisation could lead to renewable and sustainable fuel source utilising a solid waste feedstock such as ELTs.


Assuntos
Óleos , Pirólise , Temperatura Alta , Hidrocarbonetos , Resíduos Sólidos , Temperatura
12.
Multimedia | Recursos Multimídia | ID: multimedia-9326

RESUMO

O uso de ingredientes culinários processados como óleos, gorduras, sal e açúcar são comumente utilizados ao temperar e cozinhar alimentos e criar preparações culinárias. Em uma alimentação adequada e saudável, esperamos que esses produtos sejam utilizados com moderação para não trazer prejuízos à saúde.


Assuntos
Dieta Saudável , Culinária , Cloreto de Sódio na Dieta/efeitos adversos , Gorduras na Dieta/efeitos adversos , Óleos/efeitos adversos , Sacarose na Dieta/efeitos adversos , Comportamento Alimentar
13.
PLoS One ; 16(10): e0257850, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34606518

RESUMO

Running-in is an important and relatively complicated process. The surface morphology prior to running-in affects the surface morphology following the running-in process, which in turn influences the friction and wear characteristics of the workpiece. Therefore, the establishment of a model for running-in surface morphology prediction is important to investigate the process and optimize the surface design. Black-box models based on machine learning have robust complex object simulation performance. In this paper, five common machine learning methods are applied to establish running-in modeling performance based on surface morphology parameters. The support vector machine has the best model performance. The change law of the surface morphology parameters is obtained based on model testing, and the surface morphology optimization is explored. When better oil storage capacity is required, the recommendation is to increase the Sq, Sdq and Sk surface parameter values while setting medium Sdc and Sdr surface parameter values. When a lower coefficient of friction (COF) is required, Sdc and Sdr should be decreased, and Sq and Sdq should be increased. When better support performance is required, Sdc, Sdq, and Sdr should be increased. This article provides a solution to establish a link between surface design and functional performance in the steady wear stage, further filling the gap in quality monitoring of lifecycles.


Assuntos
Fricção , Aprendizado de Máquina , Teste de Materiais , Propriedades de Superfície , Simulação por Computador , Árvores de Decisões , Previsões , Lubrificação , Óleos/química , Máquina de Vetores de Suporte
14.
Water Sci Technol ; 84(8): 2040-2056, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34695029

RESUMO

To obtain a kind of superhydrophobic sponge with high oil and water selectivity, the MS/TiO2/PDMS sponge was prepared via a two-step hydrophobic fabrication based on the melamine sponge (MS), tetrabutyl titanate (TBOT), and polydimethylsiloxane (PDMS). The effects of modification time, the concentrations of TBOT and PDMS on the properties of the MS/TiO2/PDMS sponge were studied, and the separation mechanism was also discussed based on the interaction between the oil and the surface of the MS/TiO2/PDMS sponge. The results suggest that under optimal conditions, the MS/TiO2/PDMS sponge show superhydrophobicity. The contact angle and adsorption capacity for oil of the MS/TiO2/PDMS sponge are 149.2° and 98.5 g·g-1, respectively, and they can be recycled for about 25 cycles after oil-water separation test. This study prepares a new composite material with high oil-water selectivity, which is a good foundation for the development and research of new oil adsorbents.


Assuntos
Dimetilpolisiloxanos , Óleos , Interações Hidrofóbicas e Hidrofílicas , Titânio , Triazinas
15.
J Photochem Photobiol B ; 223: 112303, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34509718

RESUMO

Hypericin (Hy) is a hydrophobic photosensitizer used in photodynamic therapy for cancer therapeutic. In this study, Hy-loaded oil-in-water (O/W) nanoemulsions (NEs) were produced by the ultrasonication method combing different biocompatible oils and surfactants to enhance Hy aqueous solubility and bioavailability. Experimental parameters were optimized by the characterization of droplet size, zeta potential, and physicochemical properties. In vitro studies based on the release profile, cytotoxicity, cell morphology, and Hy intracellular accumulation were assayed. Hy at 100 mg L-1 was incorporated into the low viscosity (~0.005 Pa s) NEs with spherical droplets averaging 20-40 nm in size and polydispersity index <0.02. Hy release from the NE was significantly higher (4-fold) than its suspension (p < 0.001). The NEs demonstrated good physical stability during storage at 5 °C for at least six months. The Hy-loaded NEs exhibited an IC50 value 6-fold lower than Hy suspension during PDT against breast cancer cell lines (MCF-7). Cell microscopy imaging confirmed the increased cytotoxic effects of Hy-loaded NEs, showing damaged and apoptotic cells. Confocal laser scanning microscopy evidenced greater Hy delivery through NE into MCF-7 cells followed by improved intracellular ROS generation. Our results suggest that the Hy-loaded NEs can improve hypericin efficacy and assist Hy-PDT's preclinical development as a cancer treatment.


Assuntos
Antracenos/química , Emulsões/química , Nanoestruturas/química , Perileno/análogos & derivados , Fotoquimioterapia/métodos , Radiossensibilizantes/química , Antracenos/metabolismo , Antracenos/farmacologia , Apoptose/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Liberação Controlada de Fármacos/efeitos da radiação , Estabilidade de Medicamentos , Humanos , Luz , Células MCF-7 , Óleos/química , Perileno/química , Perileno/metabolismo , Perileno/farmacologia , Radiossensibilizantes/metabolismo , Radiossensibilizantes/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Sonicação , Temperatura , Água/química
16.
Sensors (Basel) ; 21(17)2021 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-34502624

RESUMO

Remote sensing techniques currently used to detect oil spills have not yet demonstrated their applicability to dispersed forms of oil. However, oil droplets dispersed in seawater are known to modify the local optical properties and, consequently, the upwelling light flux. Theoretically possible, passive remote detection of oil droplets was never tested in the offshore conditions. This study presents a field experiment which demonstrates the capability of commercially available sensors to detect significant changes in the remote sensing reflectance Rrs of seawater polluted by six types of dispersed oils (two crude oils, cylinder lubricant, biodiesel, and two marine gear lubricants). The experiment was based on the comparison of the upwelling radiance Lu measured in a transparent tank floating in full immersion in seawater in the Southern Baltic Sea. The tank was first filled with natural seawater and then polluted by dispersed oils in five consecutive concentrations of 1-15 ppm. After addition of dispersed oils, spectra of Rrs noticeably increased and the maximal increase varied from 40% to over three-fold at the highest oil droplet concentration. Moreover, the most affected Rrs band ratios and band differences were analyzed and are discussed in the context of future construction of algorithms for dispersed oil detection.


Assuntos
Poluição por Petróleo , Petróleo , Óleos , Poluição por Petróleo/análise , Tecnologia de Sensoriamento Remoto , Água do Mar
17.
J Environ Manage ; 300: 113756, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34534758

RESUMO

The quality of heavy oil electric desalting wastewaters (HO-EDWs) affects the effectiveness of refinery wastewater treatment plants. In this study, an integrated coagulation-ozonation (ICO) process was used to pretreat HO-EDWs and the influences on the characteristics of dissolved organic pollutants (DOPs) were investigated. Coagulation using aluminum sulfate removed 39% of soluble chemical oxygen demand (SCOD), 21% of dissolved organic carbon (DOC), 57% of petroleum hydrocarbons and 38% of polar oils from Liaohe HO-EDWs and the biodegradability was greatly improved. Ozonation removed 33% of SCOD and 88% of polar oils from the coagulated HO-EDWs. Most species of aromatic compounds, phenols, aliphatic acids, anilines and naphthenic acids with high C numbers and ring numbers were degraded and the unsaturation degrees of DOPs significantly decreased under ozonation. As a result, the biodegradability was further improved and the acute toxicity towards Vibrio fischeri was substantially reduced. Some OxS1 species and organic nitrogen compounds in HO-EDWs were penetrated through ozonation and caused the residual biotoxicity. The results demonstrate the potential of ICO pretreatment for improving the quality of refractory HO-EDWs.


Assuntos
Poluentes Ambientais , Ozônio , Poluentes Químicos da Água , Óleos , Águas Residuárias , Poluentes Químicos da Água/análise
18.
ScientificWorldJournal ; 2021: 9970957, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34512205

RESUMO

In developed countries, the ideas of ecological agricultural production, continuous cycle, and waste-free production technologies have gained popularity. The effect from the production and consumption of ecological agricultural products is determined by the least harm to the environment, increasing the competitiveness of products, and receiving additional profit from increasing prices for higher quality products. The production of organically safe products is based on the principle of biologization, i.e., the widespread use of biological preparations, a high proportion of legumes (sources of nitrogen), and avoiding chemical plant protection products, transgenic plants, and genetically modified organisms (GMOs). This study aims to increase the productivity of safflower and improve the physicochemical and biological indicators of dark chestnut soils through the use of biologized technologies in the organic farming system. Standard methods for assessment and statistical analysis of physical and chemical parameters of soils were carried out in zone 1 of West Kazakhstan. This made it possible to identify the most optimal technology for the cultivation of safflower. The study results showed that under the influence of the phytomeliorative action of safflower in the 0-20 cm layer of dark chestnut soils, one could note an increase in the content of nitrate nitrogen by 5.95%, an increase in the content of mobile phosphorus by 5.22%, and soil loosening by 0.010 g/cm3, with the structure of the soil being 64.43%. Strong biological activity of the soil was established by the crops of safflower. The highest yield of safflower oil about 0.23 t/ha with an oil content of 30.1% was obtained using the biologized technology option. The use of biological technology, along with biological yields, increases oil yield by 0.06 t/ha or 28.06%.


Assuntos
Agricultura Orgânica/métodos , Solo , Carthamus tinctorius/crescimento & desenvolvimento , Produtos Agrícolas/crescimento & desenvolvimento , Biomarcadores Ambientais , Fertilizantes/análise , Fungicidas Industriais , Cazaquistão , Nitrogênio/análise , Óleos/análise , Fósforo/análise , Plantas Daninhas , Óleo de Cártamo , Estações do Ano , Silagem , Solo/química , Poluentes do Solo/análise
19.
Crit Rev Toxicol ; 51(5): 418-455, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-34494504

RESUMO

Paraffin waxes and white mineral oils are distinct petroleum products separated from a common feedstock by crystallization, where only n-alkanes, iso- and cyclo-alkanes with a linear backbone of ∼ 20 carbon atoms long, selectively crystalize out from the oil to form the wax, which is solid at room temperature, whereas oils remain liquid. Up until the 90's, these differences were reflected in separated regulatory assessments. A paradigm shift occurred when Fischer 344 rats (F-344) developed liver epithelioid granuloma following exposure to low and medium viscosity oils or waxes. This lesion was used as common denominator between these products to be jointly assessed under the common term "mineral hydrocarbons - MHC", obviating compositional differences. This regulatory paradigm dominated for the next 30 years, exacerbated by the EFSA 2012 evaluation using the analytical term "MOSH" (mineral oil saturated hydrocarbons) which encompassed these products under single chromatography fraction. The reconstruction of historical developments, together with recent EFSA-sponsored studies of toxicity and accumulation and supporting literature, has allowed us to understand the etiology of the F-344 rat hepatic epithelioid granuloma, which is presented in an adverse outcome pathway (AOP). Considering chemical composition, it clearly demonstrates that the hepatic effects in F-344 rats caused by linear alkanes of waxes are irrelevant for humans. Waxes are thus not MOSH and should thus be evaluated on their own merit. The term MOSH should not include n-alkanes and be exclusively used to mineral oil fractions when considering their chemical makeup for a relevant human hazard assessment.


Assuntos
Hidrocarbonetos , Óleo Mineral , Animais , Hidrocarbonetos/toxicidade , Óleo Mineral/toxicidade , Óleos , Ratos , Medição de Risco , Ceras/toxicidade
20.
Mar Pollut Bull ; 172: 112899, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34523424

RESUMO

Toxicity thresholds for dissolved oil applied in tropical ocean risk assessments are largely based on the sensitivities of temperate and/or freshwater species. To explore the suitability of these thresholds for tropical habitats we experimentally determined toxicity thresholds for eight tropical species for a partially weathered gas condensate, applied the target lipid model (TLM) to predict toxicity of fresh and weathered condensates and compared sensitivities of the tropical species with model predictions. The experimental condensate-specific hazard concentration (HC5) was 167 µg L-1 total aromatic hydrocarbons (TAH), with the TLM-modelled HC5 (78 µg L-1 TAH) being more conservative, supporting TLM-modelled thresholds for tropical application. Putative species-specific critical target lipid body burdens (CTLBBs) indicated that several of the species tested were among the more sensitive species in the TLM database ranging from 5.1 (coral larvae) to 97 (sponge larvae) µmol g-1 octanol and can be applied in modelling risk for tropical marine ecosystems.


Assuntos
Antozoários , Poluentes Químicos da Água , Animais , Ecossistema , Água Doce , Óleos , Poluentes Químicos da Água/toxicidade
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