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Methanol (Non-Cancer)

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9,797 References Were Found:

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Development of a stability-indicating LC method for determination of a synthetic chalcone derivative in a nanoemulsion dosage form and identification of the main photodegradation product by LC-MS

Authors: Mattos, CB; Deponti, VB; Barreto, F; Simoes, CMO; Andrighetti-Frohner, CR; Nunes, RJ; Steindel, M; Teixeira, HF; Koester, LS (2012) Journal of Pharmaceutical and Biomedical Analysis 70:652-656. HERO ID: 1450328

[Less] This study aimed to develop and validate a stability indicating LC for the determination of 5-(2-benzoylethenyl)-N-benzyl-2 . . . [More] This study aimed to develop and validate a stability indicating LC for the determination of 5-(2-benzoylethenyl)-N-benzyl-2 methoxybenzenesulfonamide (SCD - a synthetic chalcone derivative), and evaluate the degradation profile of the compound under different stress conditions recommended by International Conference on Harmonization (ICH). Chromatographic separation was performed on a silica C18 column, methanol-water mobile phase 70:30 (v:v), pH 5.0 adjusted with the addition of trifluoroacetic acid (TFA) at a flow rate of 1.0 mL min(-1); detection by UV absorption at 330 nm. The method was validated for linearity, precision, accuracy, robustness and specificity. The SCD was subjected to forced degradation and peak photodegradation product was well separated from the pure substance, with retention times significantly different, indicating the specificity of the method. Second-order degradation kinetics of SCD was observed under photodegradation and base-induced degradation. In order to identify the product formed under photodegradation, liquid chromatography-tandem mass spectrometry (LC-MS/MS) was performed. These results indicate that the method can be successfully used in order to assay SCD in a nanoemulsion dosage form, and that this formulation has a protective effect over SCD degradation. (C) 2012 Elsevier B.V. All rights reserved.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Analysis of perfluoroalkyl substances in waters from Germany and Spain

Authors: Llorca, M; Farré, M; Picó, Y; Müller, J; Knepper, TP; Barceló, D (2012) Science of the Total Environment 431:139-150. HERO ID: 1450669

[Less] Water has been identified as one of the main routes of human exposure to perfluoroalkyl substances (PFASs). . . . [More] Water has been identified as one of the main routes of human exposure to perfluoroalkyl substances (PFASs). This work assessed the presence of 21 PFASs along the whole water cycle using a new fast and cost effective analytical method based on an online sample enrichment followed by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). The method was validated for different types of matrices (ultrapure water, tap water and treated wastewater). The quality parameters for the 21 selected compounds presented good limits of detection (LOD) and quantification (LOQ) ranging, in general, from 0.83-10 ng/L to 2.8-50 ng/L, respectively. The method was applied to assess the occurrence of PFASs in 148 water samples of different steps along the whole water cycle, including: mineral bottled water, tap water, river water and treated effluent wastewater, from Germany to Spain. In addition, in order to prove the good performance of the online analytical method, the analysis of PFASs was carried out in parallel using a method based on offline anionic solid phase extraction (SPE) followed by LC-MS/MS. Consistent results were obtained using both approaches. The more frequently found compounds were perfluoroalkyl acids, such as the perfluorobutanoic acid which was in the 54% of the tap water samples investigated with concentrations in the range between 2.4 and 27 ng/L, the perfluoroheptanoic acid (0.23-53 ng/L) and perfluorooctanoic acid (0.16-35 ng/L), and the sulphonate perfluorooctanesulfonate (0.04-258 ng/L) which was the second more frequent compound and also the compound found in with the higher concentration. It should be remarked that the 88% of the samples analyzed presented at least one of the compounds at quantifiable concentrations. In addition, PFASs including short chain compounds were proved to be prevalent in drinking water, and the 50% of the drinking water samples showed quantifiable concentrations of PFASs. It should be said that the great majority of the samples may not pose an immediate health risk to consumers, and just 6 of the drinking water samples presented concentrations of PFOS exceeding the Provisional Health Advisory (PHA) level established by the Office of Water from the USEPA for PFOS, which was set in 200 ng/L.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Multivitamin Analysis of Fruits, Fruit-Vegetable Juices, and Diet Supplements

Authors: Plonka, J; Toczek, A; Tomczyk, V (2012) HERO ID: 1451395

[Less] Vitamins are organic compounds that are required for various biological functions. In general, vitamins . . . [More] Vitamins are organic compounds that are required for various biological functions. In general, vitamins are not synthesized in the human body, but lack or deficiency of them may lead to certain diseases. Determinations of 11 vitamins in various products were performed, which included ascorbic acid (C), seven vitamins of the B group (thiamine B-1, riboflavin B-2, nicotinamide B-3, pantothenic acid B-5, pyridoxine B-6, folic acid B-9, and cyanocobalamin B-12), as well as three fat-soluble vitamins (retinol A, cholecalciferol D-3, and alpha-tocopherol E). A column with RP18 stationary phase and a diode array detector with properly selected analytical wavelengths for each compound were used. A gradient of trifluoroacetic acid in water with methanol was used as the mobile phase. Limits of quantification in the range of 0.70-2.90 mu g/mL for water-soluble vitamins and 1.85-15.84 mu g/mL for fat-soluble vitamins were obtained. Those values are sufficient for determinations of the aforementioned compounds in foodstuff. The developed procedure of sample preparation together with chromatographic system can be used for food quality monitoring in the food industry.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Simultaneously preparative purification of Huperzine A and Huperzine B from Huperzia serrata by macroporous resin and preparative high performance liquid chromatography

Authors: Zhang, H; Liang, Hao; Kuang, P; Yuan, Q; Wang, Yan (2012) Journal of Chromatography B 904:65-72. HERO ID: 1453461

[Less] Huperzine A (HupA) and Huperzine B (HupB) are natural alkaloids existed in Lycopodium plants. They . . . [More] Huperzine A (HupA) and Huperzine B (HupB) are natural alkaloids existed in Lycopodium plants. They both have potential clinical application for treating Alzheimer's Disease (AD). For the purpose of better utilizing the limited plant resources, a quick and low cost method to separate and purify HupA and HupB from Huperzia serrata (Thunb. ex Murray) was established in this paper. Low polarity macroporous resin SP850 was selected from eight kinds of resins during initial purification. Trifluoroacetic acid (TFA) was proved to be the best acid modifier reagent among all acids used in our experiment for improving separation. HupA and HupB were baseline separated on a C18 column by preparative high performance liquid chromatography (Preparative HPLC), the optimal gradient mobile phase system contained methanol increasing from 15% (v/v) to 35% (v/v) and 0.1% (v/v) TFA within the water. The purity of HupA and HupB obtained was 99.1% and 98.6%, respectively, and the total recovery for them was 83.0% and 81.8%, respectively. (C) 2012 Elsevier B.V. All rights reserved.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

The promoting effect of adsorbed carbon monoxide on the oxidation of alcohols on a gold catalyst

Authors: Rodriguez, P; Kwon, Y; Koper, MT (2011) Nature Chemistry 4:177-182. HERO ID: 1038088

[Less] In heterogeneous catalysis and electrocatalysis, adsorbed carbon monoxide typically acts as a poison . . . [More] In heterogeneous catalysis and electrocatalysis, adsorbed carbon monoxide typically acts as a poison or poisoning intermediate in the oxidation of alcohols. However, gold as an (electro)catalyst often exhibits unexpected properties. Here we show that carbon monoxide irreversibly adsorbed on a Au(111) surface in aqueous alkaline media can act as a promoter for the electrocatalytic oxidation of certain alcohols, in particular methanol. In comparison with bare Au(111), the onset potential for methanol oxidation is significantly lower in the presence of adsorbed CO, and formation of the main methanol oxidation products-formaldehyde and formic acid-is enhanced. By studying the effect of adsorbed CO on the oxidation of other alcohols on gold, we conclude that the presence of adsorbed CO promotes beta-hydrogen elimination, that is, C-H bond breaking. Apart from its importance to gold catalysis, this is an unanticipated example of promotion effects by co-adsorbed small molecules in electrocatalysis.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Combinatorial Effects of Charge Characteristics and Hydrophobicity of Silk Fibroin on the Sorption and Release of Charged Dyes

Authors: Wongpanit, P; Rujiravanit, R (2011) Journal of Biomaterials Science, Polymer Edition. HERO ID: 1050990

[Less] The present study was designed to examine the influence of the charge characteristics of silk fibroin . . . [More] The present study was designed to examine the influence of the charge characteristics of silk fibroin on the sorption and release of charged dyes by varying the pH values of the sorption and release media as well as types of charged dyes. Negatively charged dyes (phenol red and chromotrope 2R) and positively charged dyes (crystal violet and indoine blue) were used as the model compounds. Silk fibroin films were prepared by using a solution casting technique. The prepared films were then treated with an aqueous methanol solution or annealed with water to control their conformation. The sorption behavior of the model compounds made by the methanol-treated and water-annealed silk fibroin films was investigated. Compared to the water-annealed silk fibroin films, a higher hydrophobicity of the methanol-treated silk fibroin films caused a higher sorption of the hydrophobic dyes. The dye molecules had a fairly high affinity to the silk fibroin film, even though the dye and the matrix possessed the same charge. However, in the presence of two charged groups in a single dye molecule, the electrostatic repulsion become more dominant. Stronger interaction was observed when the charges of the film and the dye were opposite. The results of dye sorption and release experiments showed that the degree of synergism or competition between electrostatic and hydrophobic interactions directly depended on the charges and chemical structure of the dye molecules and the environmental pH conditions of the existing silk fibroin film.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Improvement of dispersion state and charge separation efficiency of hybrid films of ZnO nanoparticle/conjugated polymers by utilizing methanol as a volatile dispersant

Authors: Tanita Hirunprateep; Nisanart Traiphol; Ruttayapon Potai; Rakchart Traiphol (2011) Synthetic Metals. HERO ID: 1000519

[Less] This contribution introduces an efficient method for fabricating hybrid films of ZnO nanoparticle/conjugated . . . [More] This contribution introduces an efficient method for fabricating hybrid films of ZnO nanoparticle/conjugated polymers with improved charge separation efficiency. Methanol is utilized as a volatile dispersant for promoting the dispersion of ZnO nanoparticles in chlorobenzene. The increase of methanol concentration from 0 to 20% (v/v) results in systematic improvement of the particle dispersion. The suspensions of ZnO nanoparticles in these solvents are used to prepare hybrid films of poly[2-methoxy-5-(2′-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV) and regioregular poly(3-hexylthiophene) (P3HT). The morphologies and optical properties of the hybrid films, prepared by spin casting, are investigated by atomic force microscopy, UV/vis absorption and photoluminescence (PL) spectroscopy. The hybrid films obtained from all systems are continuous and exhibit relatively smooth surface. The extent of polymeric chain aggregation in the hybrid films is hardly affected by the variation of solvent. However, the drop of about 60% of PL intensity is detected when the methanol is added into ZnO/MEH-PPV solution prior to the film preparation. The drastic decrease of PL intensity indicates significant improvement of charge separation efficiency in the hybrid films. The investigation of ZnO/P3HT hybrid films shows consistent results. Our approach is very efficient because the methanol completely evaporates during the fabrication of hybrid film.