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1.
Biomed Chromatogr ; 34(10): e4924, 2020 Oct.
Article in English | MEDLINE | ID: mdl-32559819

ABSTRACT

Monitoring the trace amount of chemicals in various samples remains a challenge. This study was conducted to develop a new solid-phase microextraction (SPME) system (inside-tube SPME) for trace analysis of n-hexane in air and urine matrix. The inside-tube SPME system was prepared based on the phase separation technique. A mixture of carbon aerogel and polystyrene was loaded inside the needle using methanol as the anti-solvent. The air matrix of n-hexane was prepared in a Tedlar bag, and n-hexane vapor was sampled at a flow rate of 0.1 L/min. Urine samples spiked with n-hexane were used to simulate the sampling method. The limit of detection using the inside-tube SPME was 0.0003 µg/sample with 2.5 mg of adsorbent, whereas that using the packed needle was 0.004 µg/sample with 5 mg of carbon aerogel. For n-hexane analysis, the day-to-day and within-day coefficient variation were lower than 1.37%, with recoveries over 98.41% achieved. The inside-tube SPME is an inter-link device between two sample preparation methods, namely, a needle trap device and an SPME system. The result of this study suggested the use of the inside-tube SPME containing carbon aerogel (adsorbent) as a simple and fast method with low cost for n-hexane evaluation.


Subject(s)
Air/analysis , Hexanes , Solid Phase Microextraction/instrumentation , Solid Phase Microextraction/methods , Environmental Exposure , Equipment Design , Hexanes/analysis , Hexanes/isolation & purification , Hexanes/urine , Humans , Limit of Detection , Linear Models , Reproducibility of Results
2.
Chemosphere ; 253: 126684, 2020 Aug.
Article in English | MEDLINE | ID: mdl-32464772

ABSTRACT

The use of Fusarium solani fungi in an expanded perlite packed biofilter was investigated for the treatment of a hexane polluted waste gas stream using selected ion flow tube mass spectrometry (SIFT-MS). The latter analytical technique proved to be of utmost importance to evaluate the performance of the biofilter at high time resolution (seconds) under various transient conditions, analogous to industrial situations. The biofilter was operational for 277 days with inlet loads varying between 1 and 14 g m-3 h-1 and applying an empty bed residence time of 116 s. The results showed a positive behaviour of the biofilter against different types of disruptions such as: (i) changes in the relative humidity of the inlet gas, (ii) stopping the carbon supply for 1, 5 and 10 days, (iii) varying the inlet hexane concentration (step increases and intermittent pulses) and (iv) limiting the availability of nutrients. X-ray imaging (both conventional 2D µCT and X-ray fluorescence, XRF) was applied for the first time on biofilter media in order to get insight in the internal structure of expanded perlite and to visualise the biomass growth. The latter in combination with online porosity measurements using SIFT-MS provides fundamental information regarding the biofiltration process.


Subject(s)
Aluminum Oxide , Environmental Pollutants/isolation & purification , Filtration/methods , Fungi , Hexanes/isolation & purification , Silicon Dioxide , Air Pollutants/isolation & purification , Biodegradation, Environmental , Biomass , Fusarium/growth & development , Fusarium/metabolism , Spectrum Analysis/methods
3.
J Immunoassay Immunochem ; 40(5): 459-472, 2019.
Article in English | MEDLINE | ID: mdl-31204615

ABSTRACT

Several plants of Satureja genus have shown anti-tumor activity. We investigated the antileukemia effects of different fractions of Satureja hortensis (Summer savory). The growth inhibitory effect of S. hortensis fractions on K562 and Jurkat leukemia cells were determined by MTT assay. The most effective fractions were analyzed by flow cytometry and colorimetric assay for apoptosis induction and cell cycle changes. Various fractions from S. hortensis showed growth inhibitory effects on leukemia cells, among them two hexane and dichloromethane fractions with IC50 values of 32.1-47.8 µg/ml (K562) and 44.3-45.7 µg/ml (Jurkat) were the most effective. According to annexin V staining, both of these fractions significantly induced apoptosis at 50µg/ml in K562 (hexane; 73.06 ± 5.11% and dichloromethane; 96.14 ± 2.33%) and Jurkat cells (hexane; 78.85 ± 11.9% and dichloromethane; 94.05 ± 2.47%) 48 h after treatment. They increased cell accumulation in sub-G1 phase (>50%, p < .001) and decreased number of cells in G0-G1, S and G2M phases. The fractions significantly increased the caspase-3 activity in both cell lines (≈2.5-3.5 fold of untreated cells). Hexane and dichloromethane fractions of S. hortensis had the capacity to induce death and change the cell cycle distribution in leukemia cells; therefore they might be good candidates for more studies in regard to their possible therapeutic usefulness in leukemia.


Subject(s)
Cell Cycle/drug effects , Cell Death/drug effects , Hexanes/pharmacology , Leukemia, T-Cell/pathology , Methylene Chloride/pharmacology , Plant Extracts/pharmacology , Satureja/chemistry , Cell Proliferation/drug effects , Colorimetry , Dose-Response Relationship, Drug , Hexanes/chemistry , Hexanes/isolation & purification , Humans , Jurkat Cells , K562 Cells , Leukemia, T-Cell/drug therapy , Methylene Chloride/chemistry , Methylene Chloride/isolation & purification , Plant Extracts/chemistry , Plant Extracts/isolation & purification
4.
Biomed Pharmacother ; 111: 403-413, 2019 Mar.
Article in English | MEDLINE | ID: mdl-30594779

ABSTRACT

BACKGROUND: Annona muricata is used in traditional African medicine to manage urinary obstruction. In this study, we hypothesized that hexane fraction of Annona muricata (HFAM) seeds will ameliorate testosterone propionate (Tp)-induced benign prostatic hyperplasia (BPh). METHODS: Castrated rats were assigned into six groups: non-castrated control, castrated control, castrated rats that received Tp (BPh group), [BPh+HFAM], [BPh+HFAM + finasteride], [BPh + finasteride]. RESULTS: The BPh rats had 3.8 and 3.9 folds increases in prostatic and organo-somatic weight, while treatment with HFAM alone and [HFAM + finasteride] decreased prostatic weight by 22% and 34%, respectively. BPh increased the activities of serum and prostatic total acid phosphatase by 95% and 121%; and activities of serum and prostatic alkaline phosphatase by 54% and 281%, respectively. Serum and prostatic lipid peroxidation were increased by 44% and 82%, respectively, in BPh rats with a concomitant decrease in prostatic superoxide dismutase by 73%. In BPh rats, serum and prostatic myeloperoxidase increased by 4.0 and 2.0 folds, while serum nitric oxide increased by 2.4 folds, respectively. Strong expression of inducible nitric oxide synthase, Bcl2, beta-catenin, androgen and estrogen receptors were observed in BPh rats. Importantly, treatment with HFAM or finasteride (or combination) attenuated prostatic weight, inflammatory and antioxidant indices in BPh rats. CONCLUSION: HFAM may serve as novel therapeutic agent against BPh.


Subject(s)
Annona , Plant Extracts/therapeutic use , Prostatic Hyperplasia/chemically induced , Prostatic Hyperplasia/drug therapy , Seeds , Testosterone/toxicity , Animals , Hexanes/isolation & purification , Hexanes/therapeutic use , Male , Plant Extracts/isolation & purification , Prostatic Hyperplasia/pathology , Rats , Rats, Wistar
5.
Daru ; 26(2): 105-116, 2018 Dec.
Article in English | MEDLINE | ID: mdl-30242672

ABSTRACT

PURPOSE: Cancer disease is the second cause of death in the world. Now a days, high percentage of drugs, which are involved in treatment of cancers, have natural origin. Introduction of microalgae strains as anti-cancer drugs origin is a valuable approach for cancer therapy. METHODS: In the present study we describe the isolation, characterization, and anti-proliferative activity of a new microalga strain (Picochlorum sp. RCC486) from Iran. The cytotoxic activity of four different algal extracts including methanol, ethyl acetate, chloroform, and hexane were evaluated against MDA-MB-231, MCF-7, Hep-G2, and A-549 cell liens. Cell viability was determined using MTT assay in both monolayer and spheroids 3D cultures. The apoptosis was confirmed by different methods such as AO/EB and Annexin V-FITC/PI double staining, caspase-3 colorimetric assay, ROS and MMP assay. RESULTS: The results of MTT assay and fluorescent double staining confirmed that methanol and ethyl acetate extracts showed the best cytotoxic activity against the cancer cell lines. The production of ROS, caspase-3 activity and depolarized MMP were quite significant in MDA-MB-231 cell line treated with methanol and ethyl acetate extracts. CONCLUSION: In this research we revealed that cytotoxicity and apoptotic effects of the methanol and ethyl acetate extracts in human cancer cells make them good candidates for further pharmacological studies to discover effective drugs for cancer therapy. Graphical abstract The present study describes the isolation, characterization, and anti-proliferative activity of different extracts of a new microalga strain (Picochlorum sp. RCC486) from Iran. The antiproliferative and apoptosis inducing activity of ethyl acetate and methanol extracts with high content of phenol and carotenoid make them as good candidates for further pharmacological studies to discover effective drugs for cancer therapy.


Subject(s)
Antineoplastic Agents/isolation & purification , Antineoplastic Agents/pharmacology , Biological Factors/isolation & purification , Biological Factors/pharmacology , Cell Culture Techniques/methods , Microalgae/chemistry , A549 Cells , Acetates/isolation & purification , Acetates/pharmacology , Antineoplastic Agents/chemistry , Biological Factors/chemistry , Cell Proliferation/drug effects , Cell Survival/drug effects , Chloroform/isolation & purification , Chloroform/pharmacology , Drug Screening Assays, Antitumor , Hep G2 Cells , Hexanes/isolation & purification , Hexanes/pharmacology , Humans , MCF-7 Cells , Methanol/isolation & purification , Methanol/pharmacology , Reactive Oxygen Species , Spheroids, Cellular/cytology , Spheroids, Cellular/drug effects , Tumor Cells, Cultured
6.
Environ Sci Pollut Res Int ; 24(7): 6390-6396, 2017 Mar.
Article in English | MEDLINE | ID: mdl-27026546

ABSTRACT

Heterogeneous photocatalytic oxidation systems using titanium dioxide (TiO2) have been extensively studied for the removal of several volatile organic compounds (VOCs). The addition of noble metals such as palladium on TiO2 may improve photocatalytic activity by increasing charge separation efficiency. In this work, palladium was impregnated on TiO2 and the efficiency of the new catalyst was tested and compared with that of pure TiO2. Pd was impregnated on TiO2 by the reduction method, using NaBH4, and was characterized by XRD, XPS, UV-Vis, and H2 chemisorption. The photocatalytic tests were performed in an annular coated-wall reactor using octane, isooctane, n-hexane, and cyclohexane at inlet concentrations varying from 100 to 120 ppmv. Compared with pure TiO2 film, the photocatalytic activity of TiO2 impregnated with 1 wt% of palladium was improved. All the aforementioned analytical techniques confirmed the presence of Pd incorporated into the structure of TiO2, and the conversion rates were studied in a broad range of residence times, yielding up to 90 % or higher rates in 40 s of residence time, thus underscoring the relevant contribution of the technology.


Subject(s)
Air Pollutants/isolation & purification , Palladium/chemistry , Titanium/chemistry , Ultraviolet Rays , Adsorption , Catalysis , Hexanes/isolation & purification , Octanes/isolation & purification , Oxidation-Reduction , Photochemical Processes , X-Ray Diffraction
7.
An Acad Bras Cienc ; 88(4): 2229-2237, 2016.
Article in English | MEDLINE | ID: mdl-27991959

ABSTRACT

Piperaceae species can be found worldwide in tropical and subtropical areas and many of them have been used for centuries in traditional folk medicine and in culinary. In Brazil, species of Piperaceae are commonly used in some communities as local anesthetic and analgesic. Countrified communities have known some species of the genus Ottonia as "anestesia" and it is a common habit of chewing leaves and roots of Ottonia species to relief toothache. The purpose of this study is to report our findings on new molecules entities obtained from the roots of Ottonia anisum Spreng, in which local anesthetic activity (sensory blockage) is demonstrated for the first time in vivo guinea pig model. Phytochemical investigation led to the isolation of three amides (pipercallosidine, piperine and valeramide) and in an enriched mixture of seven amides (valeramide, 4,5-dihydropiperlonguminine, N-isobutil-6-piperonil-2-hexenamide, piperovatine, dihydropipercallosidine, pipercallosidine and pipercallpsine). Our findings demonstrated the anesthetic potential for the methanolic extract from roots, its n-hexane partition and amides from O. anisum and it is in agreement with ethnobotanical survey.


Subject(s)
Amides/isolation & purification , Anesthetics, Local/isolation & purification , Piperaceae/chemistry , Plant Extracts/chemistry , Plant Roots/chemistry , Animals , Benzodioxoles/isolation & purification , Brazil , Guinea Pigs , Hexanes/isolation & purification
8.
J Chromatogr A ; 1441: 16-23, 2016 Apr 08.
Article in English | MEDLINE | ID: mdl-26949215

ABSTRACT

A novel solid-phase microextraction (SPME) fiber was fabricated by the construction of fluorous metal organic frameworks (FMOF) and a polyimide (PI) composite strategy. As an auxiliary material, PI was expected to help FMOF particles form well-knit film on the surface of stainless steel wire and reinforce the coating, and FMOF was expected to afford a special structure to absorb, extract and enrich. Furthermore, it was explored for the headspace SPME (HS-SPME) of six volatile aromatic compounds (VACs) from water samples followed by gas chromatographic (GC) separation with flame ionization detection. Under the optimized conditions, the fiber afforded wide linear ranges (1-1000 µgL(-1)), low detection limits (0.15-0.9 µgL(-1)) and acceptable repeatability (<4.6%) and reproducibility (<7.3%). The FMOF@PI coated fiber not only offered large enhancement factors for benzene (1227) but also exhibited high extraction selectivity for benzene to other benzene homologues, hydrocarbons and phenols; for example, the extraction ratio of benzene to toluene, n-hexane and phenol could be as high as 10.2, 64.1 and 32.3, respectively. Moreover, the FMOF@PI-coated fiber afforded good thermal, water and organic solvent stabilities, and a long lifetime (over 200 times). The developed method was successfully applied to the determination of VACs in wastewater samples.


Subject(s)
Organometallic Compounds/chemistry , Resins, Synthetic/chemistry , Water Pollutants, Chemical/analysis , Water/chemistry , Benzene/isolation & purification , Flame Ionization , Hexanes/isolation & purification , Limit of Detection , Phenols/isolation & purification , Reproducibility of Results , Solid Phase Microextraction/instrumentation , Solid Phase Microextraction/methods , Stainless Steel , Toluene/isolation & purification , Wastewater/analysis
9.
J Environ Sci (China) ; 37: 163-71, 2015 Nov 01.
Article in English | MEDLINE | ID: mdl-26574100

ABSTRACT

n-Hexane is widely used in industrial production as an organic solvent. As an industrial exhaust gas, the contribution of n-hexane to air pollution and damage to human health are attracting increasing attention. In the present study, aqueous solutions of two fluorocarbon surfactants (FSN100 and FSO100) were investigated for their properties of solubilization and dynamic absorption of n-hexane, as well as their capacity for regeneration and n-hexane recovery by thermal distillation. The results show that the two fluorocarbon surfactants enhance dissolution and absorption of n-hexane, and their effectiveness is closely related to their concentrations in solution. For low concentration solutions (0.01%-0.30%), the partition coefficient decreases dramatically and the saturation capacity increases significantly with increasing concentration, but the changes for both are more modest when the concentration is over 0.30%. The FSO100 solution presents a smaller partition coefficient and a greater saturation capacity than the FSN100 solution at the same concentration, indicating a stronger solubilization for n-hexane. Thermal distillation is a feasible method to recover n-hexane from these absorption solutions, and to regenerate them. With 90sec heating at 80-85°C, the recovery of n-hexane ranges between 81% and 85%, and the regenerated absorption solution maintains its original performance during reuse. This study provides basic information on two fluorocarbon surfactants for application in the treatment of industrial n-hexane waste gases.


Subject(s)
Absorption, Physicochemical , Fluorocarbons/chemistry , Hexanes/chemistry , Hexanes/isolation & purification , Surface-Active Agents/chemistry , Water/chemistry , Feasibility Studies , Solutions , Surface Properties , Waste Products/analysis
10.
Pharm Biol ; 53(11): 1671-6, 2015.
Article in English | MEDLINE | ID: mdl-25857603

ABSTRACT

CONTEXT: Costus afer Ker Gawl. (Costaceae) is an ethnomedical plant used as therapy against inflammatory disorders. OBJECTIVE: The objective of this study was to evaluate the hematological and lipid profile analysis of hexane fraction of C. afer leaves (CAHLF) in arthritic rats. MATERIALS AND METHODS: Male albino rats were randomly distributed into seven groups of six rats each. Rats were induced with arthritis using formaldehyde and Complete Freund's Adjuvant (CFA) for 7 and 21 d, respectively. The animals were administered orally with 50, 100, and 250 mg/kg CAHLF, 10 mg/kg diclofenac and prednisolone, 0.9% NaCl (control), and 0.9% NaCl (normal). At the end of treatment periods, blood samples were withdrawn and subjected to hematological and biochemical analysis using auto-analyzer and spectrophotometric methods. RESULTS: Hematological analysis revealed that in formaldehyde- and CFA-induced arthritic rat models, 250 mg/kg CAHLF-treated groups had significantly reduced (p < 0.05) hematocrit counts (HC) (30.98 ± 1.59% and 33.55 ± 1.10%), white blood cell counts (WBC) (5.50 ± 0.35 and 4.15 ± 0.82 × 10(9)/L), and platelet counts (PC) (401.50 ± 48.94 and 246.33 ± 5.54 × 10(9)/L) compared with control HC (46.90 ± 1.92 and 41.88 ± 2.19%), WBC (11.09 ± 0.26 and 7.37 ± 0.34 × 10(9)/L), and PC (783.67 ± 59.51 and 593.83 ± 36.3 × 10(9)/L). Furthermore, blood analysis showed that CAHLF-treated groups had reduced total cholesterol, low-density lipoprotein cholesterol, and triglycerides while they had an elevated high-density lipoprotein compared with the control group. DISCUSSION AND CONCLUSION: Findings from this study indicated that CAHLF could possess immunomodulatory and hypolipidemic properties in arthritic rats. CAHLF could be considered as a source of biopharmaceutical agents in anti-arthritis drug discovery process.


Subject(s)
Arthritis, Experimental/blood , Blood Cells/metabolism , Costus , Hexanes/therapeutic use , Lipids/blood , Plant Extracts/therapeutic use , Animals , Arthritis, Experimental/drug therapy , Blood Cells/drug effects , Hexanes/isolation & purification , Hexanes/pharmacology , Male , Plant Extracts/isolation & purification , Plant Extracts/pharmacology , Plant Leaves , Rats , Rats, Wistar
11.
Environ Sci Pollut Res Int ; 21(22): 12856-67, 2014 Nov.
Article in English | MEDLINE | ID: mdl-24972657

ABSTRACT

The depollution of some gaseous streams containing n-hexane is studied by adsorption in a fixed bed column, under dynamic conditions, using granular activated carbon and two types of non-functionalized hypercross-linked polymeric resins. In order to model the process, a new neuro-evolutionary approach is proposed. It is a combination of a modified differential evolution (DE) with neural networks (NNs) and two local search algorithms, the global and local optimizers, working together to determine the optimal NN model. The main elements that characterize the applied variant of DE consist in using an opposition-based learning initialization, a simple self-adaptive procedure for the control parameters, and a modified mutation principle based on the fitness function as a criterion for reorganization. The results obtained prove that the proposed algorithm is able to determine a good model of the considered process, its performance being better than those of an available phenomenological model.


Subject(s)
Air Pollutants/isolation & purification , Hexanes/isolation & purification , Algorithms , Charcoal/chemistry , Computer Simulation , Environmental Restoration and Remediation , Gases , Kinetics , Neural Networks, Computer
12.
J Hazard Mater ; 276: 287-94, 2014 Jul 15.
Article in English | MEDLINE | ID: mdl-24887128

ABSTRACT

The performance of a fungal perlite-based biofilter coupled to a post-treatment photoreactor was evaluated over 234 days in terms of n-hexane removal, emission and deactivation of fungal spores. The biofilter and photoreactor were operated at gas residence times of 1.20 and 0.14min, respectively, and a hexane loading rate of 115±5gm(-3)h(-1). Steady n-hexane elimination capacities of 30-40gm(-3)h(-1) were achieved, concomitantly with pollutant mineralization efficiencies of 60-90%. No significant influence of biofilter irrigation frequency or irrigation nitrogen concentration on hexane abatement was recorded. Photolysis did not support an efficient hexane post-treatment likely due to the short EBRT applied in the photoreactor, while overall hexane removal and mineralization enhancements of 25% were recorded when the irradiated photoreactor was packed with ZnO-impregnated perlite. However, a rapid catalyst deactivation was observed, which required a periodic reactivation every 48h. Biofilter irrigation every 3 days supported fungal spore emissions at concentrations ranging from 2.4×10(3) to 9.0×10(4)CFUm(-3). Finally, spore deactivation efficiencies of ≈98% were recorded for the photolytic and photocatalytic post-treatment processes. This study confirmed the potential of photo-assisted post-treatment processes to mitigate the emission of hazardous fungal spores and boost the abatement performance of biotechnologies.


Subject(s)
Filtration/methods , Fungi/metabolism , Hexanes/isolation & purification , Photobioreactors
13.
Water Res ; 47(7): 2199-212, 2013 May 01.
Article in English | MEDLINE | ID: mdl-23497859

ABSTRACT

The performance of a flat-membrane biofilm reactor (MBR) for the removal of acetone, toluene, limonene and hexane at concentrations ranging from 1.3 to 3.2 mg m(-3) was investigated at different gas residence times (GRT): 60, 30, 15 and 7 s. A preliminary abiotic test was conducted to assess the mass transport of the selected volatile organic compounds (VOCs) through the membrane. A reduced transport of limonene and hexane was observed with water present over the dense side of the membrane. The presence of a biofilm attached on the dense side of the membrane following bioreactor inoculation significantly increased VOC transport. High acetone and toluene removals (>93%) were recorded in the MBR regardless of the GRT. To remediate the low hexane removal performance (RE < 24%) recorded at the initial stages of the process, a re-inoculation of the membrane with a hexane-degrading consortium embedded in silicon oil was performed. Although hexane removal did not exceed 27%, this re-inoculation increased limonene removals up to 90% at a GRT of 7 s. The absence of inhibition of hexane biodegradation by substrate competition confirmed that hexane removal in the MBR was indeed limited by the mass transfer through the membrane. Despite the low carbon source spectrum and load, the microbiological analysis of the communities present in the MBR showed high species richness (Shannon-Wiener indices of 3.2-3.5) and a high pair-wise similarity (84-97%) between the suspended and the attached biomass.


Subject(s)
Acetone/isolation & purification , Bioreactors , Cyclohexenes/isolation & purification , Hexanes/isolation & purification , Membranes, Artificial , Terpenes/isolation & purification , Toluene/isolation & purification , Water Purification/instrumentation , Bacteria/classification , Bacteria/metabolism , Biodegradation, Environmental , Denaturing Gradient Gel Electrophoresis , Limonene , Molecular Sequence Data , Time Factors , Volatile Organic Compounds/analysis , Water Pollutants, Chemical/isolation & purification
14.
Acta Bioeng Biomech ; 14(1): 23-9, 2012.
Article in English | MEDLINE | ID: mdl-22742207

ABSTRACT

Colonization of denture soft lining materials by fungi and denture plaque leads to infections of mucosa. Microorganisms such as Candida albicans colonize not only the surface of the soft liners, but they also penetrate inside those materials. Therefore the use of common disinfectants, e.g., surface active cleaners, is not a perfect solution for keeping a proper hygiene of soft linings. Modifying soft lining by silver nanoparticles (AgNP) seems to be a right way to overcome those problems. The procedure of modifying two-component silicone material by silver nanoparticles (AgNP) is presented in the article. The solubility tests for both material components have been carried out in the first stage of examinations. On the basis of test results, a solvent has been selected, being a dispersion medium for AgNPs and both soft liner components. The effective method for evaporating a solvent from the composition has been developed. Material components with various AgNP concentrations (10, 20, 40, 80, 120 and 200 ppm) have been obtained. Cured samples of the composites have been examined by SEM to confirm the effectiveness of the procedure.


Subject(s)
Denture Liners , Disinfection/methods , Metal Nanoparticles/chemistry , Silver/pharmacology , Colloids , Hexanes/isolation & purification , Magnetic Resonance Spectroscopy , Metal Nanoparticles/ultrastructure , Particle Size , Reproducibility of Results , Solubility/drug effects , Solutions
15.
J Hazard Mater ; 219-220: 176-82, 2012 Jun 15.
Article in English | MEDLINE | ID: mdl-22516522

ABSTRACT

This study investigated the removal of recalcitrant compounds in the presence of a hydrophilic compound. n-Hexane is used as a model compound to represent hydrophobic compounds. Methanol has been introduced in mixture with n-hexane in order to increase the bioavailability of n-hexane in trickle-bed-air-biofilters (TBABs). The mixing ratios investigated were: 70% methanol:30% n-hexane, and 80% methanol:20% n-hexane by volume. n-Hexane loading rates (LRs) ranged from 0.9 to 13.2 g m(-3) h(-1). Methanol LRs varied from 4.6 to 64.5 g m(-3) h(-1) and from 2.3 to 45.2 g m(-3) h(-1) depending upon the mixing ratio used. Biofilter performance, effect of mixing ratios of methanol to n-hexane, removal profile along biofilter depth, COD/nitrogen consumption and CO(2) production were studied under continuous loading operation conditions. Results have shown that the degradation of n-hexane is significantly enhanced by the presence of methanol for n-hexane LRs less than 13.2 g m(-3) h(-1). For n-hexane LR greater than 13.2 g m(-3) h(-1), even though methanol had impacted n-hexane biodegradation, its removal efficiency was higher than our previous study for biodegradation of n-hexane alone, in presence of surfactant, or in presence of benzene. On the other hand, the degradation of methanol was not impacted by the presence of n-hexane.


Subject(s)
Filtration/methods , Hexanes/isolation & purification , Methanol/chemistry , Biodegradation, Environmental , Chromatography, Gas , Nitrogen/chemistry , Volatile Organic Compounds/isolation & purification
16.
J Hazard Mater ; 199-200: 336-42, 2012 Jan 15.
Article in English | MEDLINE | ID: mdl-22118848

ABSTRACT

Polymer membranes were prepared by blending high density polyethylene (HDPE) with ethylene propylene diene terpolymer rubber (EPDM). These blend membranes were evaluated for the selective separation of n-hexane from acetone. The flux and selectivity of the membranes were determined both as a function of the blend composition and feed mixture composition. Results showed that polymer blending method could be very useful to develop new membranes with improved selectivity. Pervaporation properties could be optimized by adjusting the blend composition. The effects of blend ratio, feed composition, and penetrant size on the pervaporation process were analyzed. The permeation properties have been explained on the basis of interaction between the membrane and solvents and blend morphology. Flux increases with increasing alkane content in the feed composition.


Subject(s)
Acetone/isolation & purification , Alkenes/chemistry , Hexanes/isolation & purification , Membranes, Artificial , Polyethylene/chemistry , Rubber/chemistry , Microscopy, Electron, Scanning
17.
Anal Chem ; 83(18): 7094-101, 2011 Sep 15.
Article in English | MEDLINE | ID: mdl-21800908

ABSTRACT

Metal-organic frameworks (MOFs) were employed to design tandem molecular sieves as a dual platform for selective solid-phase microextraction (SPME) and high-resolution gas chromatographic (GC) separation of target analytes in complex matrixes. An elegant combination of a ZIF-8-coated fiber for SPME with a ZIF-8-coated capillary for GC allows selective extraction and separation of n-alkanes from complex matrixes such as petroleum-based fuel and biological fluids. The proposed tandem ZIF-8 molecular sieves not only offered good enhancement factors from 235 (hexane) to 1212 (nonane), but also exhibited wide linearity with 3 orders of magnitude for the tested linear alkanes. The limits of detection for the linear alkanes ranged from 0.46 ng L(-1) (nonane) to 1.06 ng L(-1)(hexane). The relative standard deviations of retention time, peak area, peak height, and half peak width for five replicate determinations of the tested n-alkanes at 30 ng L(-1) were 0.02-0.26%, 1.9-8.6%, 1.4-6.0%, and 1.3-7.2%, respectively. The developed tandem ZIF-8 molecular sieves were further used for the determination of linear alkanes in petroleum-based fuel and human serum. The large diversity in structure and pore size allows various combinations of MOFs for designing an MOF-based tandem molecular sieve platform to achieve different selectivities in extraction and chromatographic separation and to solve headache problems in complex real sample analysis.


Subject(s)
Alkanes/isolation & purification , Chromatography, Gas/methods , Metals/chemistry , Organic Chemicals/chemistry , Solid Phase Microextraction/methods , Alkanes/chemistry , Chromatography, Gas/instrumentation , Hexanes/chemistry , Hexanes/isolation & purification , Nanoparticles/chemistry , Petroleum/analysis
18.
J Air Waste Manag Assoc ; 61(2): 201-10, 2011 Feb.
Article in English | MEDLINE | ID: mdl-21387937

ABSTRACT

Trickle-bed air biofilters (TBABs) are suitable for treatment of hydrophilic volatile organic compounds, but they pose a challenge for hydrophobic compounds. Three laboratory-scale TBABs were used for the treatment of an airstream contaminated with different ratios of n-hexane and benzene mixtures. The ratios studied were 1:1, 2:1, and 1:3 n-hexane:benzene by volume. Each TBAB was operated at a pH of 4 and a temperature of 20 degrees C. The use of acidic-buffered nutrient solution was targeted for changing the microorganism consortium to fungi as the main biodegradation element. The experimental plan was designed to investigate the long-term performance of the TBABs with an emphasis on different mixture loading rates, removal efficiency with TBAB depth, volatile suspended solids, and carbon mass balance closure. n-Hexane loading rate was kept constant in the TBABs for comparison reasons and ranged from 4 to 22 g/(m3 x hr). Corresponding benzene loadings ranged from 4 to 43 g/(m3 x hr). Generally, benzene behavior in the TBAB was superior to that of n-hexane because of its higher solubility. n-Hexane showed improved performance in the 2:1 mixing ratio as compared with the other two ratios.


Subject(s)
Air Pollutants/isolation & purification , Benzene/isolation & purification , Hexanes/isolation & purification , Volatile Organic Compounds/isolation & purification , Carbon Dioxide/analysis , Filtration , Fungi
19.
Biotechnol Bioeng ; 108(4): 758-65, 2011 Apr.
Article in English | MEDLINE | ID: mdl-21404250

ABSTRACT

Fungal biofilters have been recently studied as an alternative to the bacterial systems for the elimination of hydrophobic volatile organic compounds (VOC). Fungi foster reduced transport limitation of hydrophobic VOCs due to their hydrophobic surface and extended gas exchange area associated to the hyphal growth. Nevertheless, one of their principal drawbacks is their slow growth, which is critical in the start-up of fungal biofilters. This work compares the use of different carbon sources (glycerol, 1-hexanol, wheat bran, and n-hexane) to reduce the start-up period and sustain high n-hexane elimination capacities (EC) in biofilters inoculated with Fusarium solani. Four parallel experiments were performed with the different media and the EC, the n-hexane partition coefficient, the biomass production and the specific consumption rate were evaluated. Biofilters were operated with a residence time of 1.3 min and an inlet n-hexane load of 325 g m(-3) (reactor) h(-1). The time to attain maximum EC once gaseous n-hexane was fed was reduced in the three experiments with alternate substrates, as compared to the 36 days needed with the control where only n-hexane was added. The shortest adaptation period was 7 days when wheat bran was initially used obtaining a maximum EC of 160 g m(-3) (reactor) h(-1) and a critical load of 55 g m(-3) (reactor) h(-1). The results were also consistent with the pressure drop, the amount of biomass produced and its affinity for the gaseous n-hexane, as represented by its partition coefficient.


Subject(s)
Biodegradation, Environmental , Bioreactors , Fungi/metabolism , Hexanes/isolation & purification , Volatile Organic Compounds/isolation & purification , Dietary Fiber/metabolism , Glycerol/metabolism , Hexanes/metabolism , Hexanols/metabolism , Hydrophobic and Hydrophilic Interactions , Volatile Organic Compounds/metabolism
20.
Arch Pharm Res ; 32(6): 823-30, 2009 Jun.
Article in English | MEDLINE | ID: mdl-19557358

ABSTRACT

Rosa rugosa is a species of rose native to eastern Asia. The root of R. rugosa has been used to treat diabetes mellitus, pain and chronic inflammatory disease, and a R. rugosa petal extract has a strong anti-oxidant effect. In the present study, we examined if solvent fractions from white rose petal extract (WRPE) had any anti-allergic or anti-atopic effects not previously reported. WRPE and butanol and hexane fractions effectively reduced systemic anaphylactic reactions and anti-dinitrophenyl (DNP) IgE-mediated passive cutaneous anaphylaxis in mice, with the greatest inhibition observed for the hexane fraction. In addition, a significant reduction of scratching behavior by mice after histamine injection suggested this fraction's potential anti-allergic effect. At the cell level, the hexane fraction markedly inhibited beta-hexosaminidase release from RBL-2H3 mast cells and suppressed the expressions of mRNA interferon-gamma and interleukin-4 cytokines produced by T helper cells (type 1 and 2). These results strongly support that the hexane fraction may have an effect on atopic dermatitis, as these 2 cell types play central roles in the pathogenesis of atopic dermatitis. In conclusion, these results suggest that either the hexane fraction or one of its components may be beneficial for the treatment of allergic diseases, including atopic dermatitis.


Subject(s)
Anti-Allergic Agents/pharmacology , Hexanes/pharmacology , Hypersensitivity, Immediate/drug therapy , Phytotherapy , Plant Extracts/pharmacology , Rosa , Anaphylaxis/chemically induced , Anaphylaxis/drug therapy , Animals , Cells, Cultured , Cytokines/metabolism , Drug Evaluation, Preclinical , Flowers/chemistry , Hexanes/isolation & purification , Histamine/pharmacology , Male , Mice , Mice, Inbred BALB C , Mice, Inbred ICR , Passive Cutaneous Anaphylaxis/drug effects , Spleen/drug effects , Spleen/metabolism , beta-N-Acetylhexosaminidases/metabolism , p-Methoxy-N-methylphenethylamine/pharmacology
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