Abstract  The reaction of nitrous acid with hydrogen peroxide leads to nitric acid as the only stable product. In the course of this reaction, peroxynitrous acid (ONOOH) and, in the presence of CO(2), a peroxynitrite-CO(2) adduct (ONOOCO(2)(-)) are intermediately formed. Both intermediates decompose to yield highly oxidizing radicals, which subsequently react with excess hydrogen peroxide to yield peroxynitric acid (O(2)NOOH) as a further intermediate. During these reactions, (15)N chemically induced dynamic nuclear polarization (CIDNP) effects are observed, the analysis of the pH dependency of which allows the elucidation of mechanistic details. The formation and decay of peroxynitric acid via free radicals NO(2)(*) and HOO(*) is demonstrated by the appearance of (15)N CIDNP leading to emission (E) in the (15)N NMR signal of O(2)NOOH during its formation and to enhanced absorption (A) during its decay reaction. Additionally, the (15)N NMR signal of the nitrate ion (NO(3)(-)) appears in emission at pH approximately 4.5. These observations are explained by proposing the intermediate formation of short-lived radical anions O(2)NOOH(*)(-) probably generated by electron transfer between peroxynitric acid and peroxynitrate anion, followed by decomposition of O(2)NOOH(*)(-) into NO(3)(-) and HO(*) and NO(2)(-) and HOO(*) radicals, respectively. The feasibility of such reactions is supported by quantum-chemical calculations at the CBS-Q level of theory including PCM solvation model corrections for aqueous solution. The release of free HO(*) radicals during decomposition of O(2)NOOH is supported by (13)C and (1)H NMR product studies of the reaction of preformed peroxynitric acid with [(13)C(2)]DMSO (to yield the typical "HO(*) products" methanesulfonic acid, methanol, and nitromethane) and by ESR spectroscopic detection of the HO(*) and CH(3)(*) radical adducts to the spin trap compound POBN in the absence and presence of isotopically labeled DMSO, respectively.

Abstract  The air oxidation of methanol to formaldehyde was investigated over MoO3, Sb2O4 and their mixtures in an integral flow reactor at atmospheric pressure, between 623 and 698 K. The effects of several operating variables Sb2O4/MoO3 ratio, temperature, space time, and methanol/air ratio on the conversion of methanol and the selectivity of the catalyst for formaldehyde formation were determined. Selectivity as high as 100% was obtained. Best operating conditions were found to be W/F of 27.5, methanol/air ratio of 0.06 at temperature of 698 for a Sb2O4/MoO3 ratio of 2. The rate expression, based on a two stage irreversible redox expression fitted the data best.

Abstract  Methanol and diesel are not very miscible, which makes it difficult to mix them together as a diesel engine fuel. Dual-fuel operation is favored, and there is potential to reduce particulate matter (PM) and NOx emissions simultaneously. In this work, an electronically controlled low-pressure common rail system was employed to deliver methanol to the inlet port, while the engineʼs original high-pressure diesel injection system was used to deliver a suitable quantity of diesel fuel for ignition. The experimental results show that the full-load power of the dual-fuel engine can reach or even exceed that of the original diesel engine when a suitable minimum pilot diesel quantity is used. Under dual-fuel conditions, smoke is reduced significantly, while a modest reduction in NOx is observed. The equivalent brake-specific fuel consumption is improved under high-load operating conditions. Especially, the dual-fuel engine shows a better fuel economy when run at a high rate of methanol addition. However, unburned hydrocarbon (HC) and carbon monoxide (CO) emissions for dual-fuel operation increase when methanol is added.

Abstract  The catalytic reduction of carbon dioxide to carbon monoxide under mild conditions using aromatic aldehydes as reductants and NHCs as organocatalysts was developed. This carbon dioxide splitting reaction provides a new method for metal-free carbon dioxide reduction and steps forward in utilizing carbon dioxide as a renewable "green" source under mild conditions. On the other hand, this reaction also shows a new economical way to oxidize aromatic aldehydes under mild conditions with carbon dioxide and could be applied in pharmaceutical synthesis.

Abstract  Methanol poisoning in Australia is now very rare as methanol has been removed from methylated spirits. In acute intoxication methanol may result in a wide range of damage to the central nervous system. Few cases have been imaged with MRI. We present two cases and their striking neuroimaging findings with a discussion of the published work on methanol poisoning.

Abstract  Analytical Institute of the University of Vienna. A method for the quantitative determination of polycyclic aromatic hydrocarbons (PAHs) in tobacco smoke condensate has been developed and was applied to the analysis of the Kentucky Reference cigarette 1R4F. The procedure uses extraction of the filters with methanol, dilution with water, automated solid-phase extraction (SPE) on a C18 column for cleanup purposes and elution with cyclohexane prior to gas chromatography-mass spectrometry for quantification. Concentration values for 17 PAHs are given and compared to results of former publications.

Abstract  9,10-Phenanthrenequinone (PQ), one of the components of atmospheric pollutants, has potent harmful effects on human health. PQ in airborne particulates collected in Nagasaki city was determined by HPLC with fluorescence derivatization. PQ extracted from airborne particulates using methanol was derivatized with benzaldehyde in the presence of ammonium acetate to give a fluorescent compound. The average concentration (mean+/-SD, n=52) of PQ found in airborne particulates collected from July 1997 to June 1998 was 0.287+/-0.128 ng m-3. Concentrations of PQ in winter were higher than those in summer. In a weekly variation study, PQ concentrations were higher during weekdays and lower at weekend. The levels of PQ were obviously correlated with those of phenanthrene (PH) that is considered as a parent compound of PQ. This observation suggested that PQ was emitted into the atmosphere from the same source as PH, or PQ was converted from PH in the atmosphere.

Abstract  The interactions of lead(II) ion with a polyhydroxylated flavonoid, the quercetin molecule, were investigated in methanol solution. The quercetin/metal stoichiometries and equilibrium stability constants for metal binding to quercetin have been determined by UV-vis spectroscopy combined with chemometrics methods. The 2:1, 1:2, and predominant 1:1 species are formed in solution. Among the three potential sites of chelation present in the quercetin structure, the catechol function presents the highest complexation power toward Pb(II), in opposition with previous results found for Al(III) complexation. This result has been confirmed by the good agreement of the experimental and theoretical features for both the electronic and vibrational spectra of the 1:1 complex. DT-DFT calculations show that the bathochromic shift of the long-wavelength band of the UV-vis spectra, that occurs upon complexation, is due to a ligand-to-metal charge transfer. The molecular structure of the ligand is not much modified by the coordination of lead at the level of the catecholate.

Abstract  Epidemiology: Almost all cases of acute methanol toxicity result from ingestion, though rarely cases of poisoning have followed inhalation or dermal absorption. The absorption of methanol following oral administration is rapid and peak methanol concentrations occur within 30?60 minutes. Mechanisms of Toxicity: Methanol has a relatively low toxicity and metabolism is responsible for the transformation of methanol to its toxic metabolites. Methanol is oxidized by alcohol dehydrogenase to formaldehyde. The oxidation of formaldehyde to formic acid is facilitated by formaldehyde dehydrogenase. Formic acid is converted by 10-formyl tetrahydrofolate synthetase to carbon dioxide and water. In cases of methanol poisoning, formic acid accumulates and there is a direct correlation between the formic acid concentration and increased morbidity and mortality. The acidosis observed in methanol poisoning appears to be caused directly or indirectly by formic acid production. Formic acid has also been shown to inhibit cytochrome oxidase and is the prime cause of ocular toxicity, though acidosis can increase toxicity further by enabling greater diffusion of formic acid into cells. Features: Methanol poisoning typically induces nausea, vomiting, abdominal pain, and mild central nervous system depression. There is then a latent period lasting approximately 12?24 hours, depending, in part, on the methanol dose ingested, following which an uncompensated metabolic acidosis develops and visual function becomes impaired, ranging from blurred vision and altered visual fields to complete blindness. Management: For the patient presenting with ophthalmologic abnormalities or significant acidosis, the acidosis should be corrected with intravenous sodium bicarbonate, the further generation of toxic metabolite should be blocked by the administration of fomepizole or ethanol and formic acid metabolism should be enhanced by the administration of intravenous folinic acid. Hemodialysis may also be required to correct severe metabolic abnormalities and to enhance methanol and formate elimination. For the methanol poisoned patient without evidence of clinical toxicity, the first priority is to inhibit methanol metabolism with intravenous ethanol or fomepizole. Although there are no clinical outcome data confirming the superiority of either of these antidotes over the other, there are significant disadvantages associated with ethanol. These include complex dosing, difficulties with maintaining therapeutic concentrations, the need for more comprehensive clinical and laboratory monitoring, and more adverse effects. Thus fomepizole is very attractive, however, it has a relatively high acquisition cost. Conclusion: The management of methanol poisoning includes standard supportive care, the correction of metabolic acidosis, the administration of folinic acid, the provision of an antidote to inhibit the metabolism of methanol to formate, and selective hemodialysis to correct severe metabolic abnormalities and to enhance methanol and formate elimination. Although both ethanol and fomepizole are effective, fomepizole is the preferred antidote for methanol poisoning.

Abstract  The structural changes occurring with the chelation of lead(II) to 3-hydroxyflavone, 5-hydroxyflavone, and 3',4'-dihydroxyflavone have been investigated by the density functional theory (DFT) method with the B3LYP functional and the 6-31G(d,p) basis set. The two effective core potentials Lanl2dz (Los Alamos) and MWB78 (Stuttgart/Dresden) were used for the Pb ion. Only the 3',4'-dihydroxyflavone ligand shows minor geometrical modifications upon chelation, whereas the two other ligands present important changes of their chromone moiety. The time dependent density functional theory (TD-DFT) has been employed to calculate the electronic absorption spectra of the 1:1 complexes of lead(II) with the three hydroxyflavones, as well in a vacuum as in methanol. The solvent effect is modeled using the self-consistent reaction field (SCRF) method with the polarized continuum model (PCM). Comparison with experimental data allows a precise assessment of the performances of the method, which appears competitive and suitable to reproduce the spectral measurements when the solvent effect is taken into account. These calculations and the molecular orbital analysis have allowed an explanation of the different behaviors of the three ligands toward Pb(II) and particularly the fact that no bathochromic shift is observed with the addition of lead(II) to a 5-hydroxyflavone solution. A complete assignment of the electronic absorption spectra of both free and complexed ligands has been carried out.

Abstract  #The effect of methanol on the levels of endogenous carnitine and its derivatives was studied in male Sprague-Dawley rats aged three months. In addition, the effect of L-carnitine supplementation on metabolic disturbances caused by methanol intoxication was studied. The rats were randomized into six groups, including two control groups. Methanol was given at 1/4 LD50 and 1/2 LD50/kg b.w. (or water in control) through an intragastric tube, and L-carnitine (or 0.9% NaCl in the control) was injected intraperitoneally. The levels of plasma L-carnitine and its derivatives were measured at selected time points for four days. Following methanol administration, the rats exhibited dose-dependent increases in L-carnitine levels and altered ratios of L-carnitine and its derivatives. L-carnitine supplementation accelerated the normalization of metabolic disturbances, as indicated by the acylcarnitine to free carnitine ratio (AC/FC). The protective effect of L-carnitine is supported by the fact that 100% of the methanol-treated rats supplemented with carnitine survived, while 8/60 rats and 27/101 rats died at methanol doses of 1/4 LD50 and 1/2 LD50, respectively, in groups without L-carnitine supplementation.

Abstract  Measurement of fine particulate and gas-phase species during the New Year's fireworks 2005 in Mainz, Germany is investigated. The chemical composition and chemically resolved size distribution of fine aerosol particles are measured at high time resolution with a time-of-flight aerosol mass spectrometer (TOF-AMS). In addition, particle number concentrations and trace gas concentrations are measured using a condensation particle counter (CPC) and a proton transfer reaction mass spectrometer (PTR-MS). The main non-refractory components of the firework aerosol are potassium, sulfate, total organics, and chloride. Increased trace gas mixing ratios of methanol, acetonitrile, acetone and acetaldehyde are observed. It is found that aerosol nitrate and the fireworks as well as the measured aromatic trace gases do not significantly affect ammonium concentrations.

Abstract  Recent attention to methanol (MeOH) as a potential alternative fuel prompted an evaluation of the chemical's effects during early pregnancy. Rats were dosed by gavage during Days 1-8 of pregnancy at 0, 1.6, 2.4, or 3.2 g MeOH/kg/day. Groups of animals were killed on Days 9, 11, or 20 of pregnancy, and maternal, embryonic, or fetal parameters were assessed, depending on the stage of pregnancy. The decidual cell response (DCR) technique was also applied to rats treated with MeOH during pseudopregnancy. Reductions in pregnant uterine and implantation site weights seen on Day 9 are the result of MeOH impedance of normal decidualization, as demonstrated by effects on the DCR. An increase in the extravasation of blood at implantation sites seen on Day 9 did not result in an increase in resorptions by Day 20. The 3.2 g/kg/day dose of MeOH produced a reduction in body weight gain by Day 9, which may be considered an indication of non-specific maternal toxicity. No effect on Day 11 or Day 20 embryo-fetal survival, or development was observed.

Abstract  Intoxication by methanol was identified in a five-week-old infant suffering from moderate metabolic acidosis. The initial serum methanol at admission was 1148 mg/dL as measured by gas chromatography. The osmolal gap and formic acid concentrations were consistent with methanol intoxication. The child was treated with folic acid and a continuous ethanol infusion and survived without any apparent permanent problems. Because expected toxic symptoms did not develop in this case, and the methanol concentrations were at levels that might be deemed to be incompatible with life, blood and urine samples were assayed by a specific enzymatic assay, and by gas chromatography/mass spectrometry (GC/MS). Positive results definitively confirmed the presence of methanol. In contrast to previous reports, the elimination of methanol in this case appeared to following first-order kinetics. If hepatic ADH activity is low in neonates and young infants, another enzyme system such as catalase may be involved to explain this data. The lack of formic acid accumulation may have been due to folic acid therapy.

Abstract  The grain boundary formation in PtRu/C catalyst obtained in a polyol process with post-treatment was investigated by scanning transmission electron microscopy, transmission electron microscopy (TEM) and High resolution TEM. The crystalline structure and surface composition of the PtRu/C catalysts were characterized by X-ray diffraction and X-ray photoelectron spectroscopy. The electrochemical activities were evaluated by CO stripping voltammetry and linear sweep voltammetry measurements in combination with in situ IR reflection-absorption spectroscopy. As-prepared isolated spherical nanoparticles on the carbon support started to interconnect after washing procedure, and the interconnection between the particles was greatly promoted by reduction post-treatment at 80 degrees C; grain boundary formation occurred in the interconnected particles with increasing reduction temperature to 200 degrees C, and the particles reconstructed severely with further increasing reduction temperature to 400 degrees C. The defects at the grain boundary served as active sites for methanol electro-oxidation by weakening COads adsorption on Pt sites and facilitating OHads formation, and the PtRu/C catalyst treated in 5% H-2/Ar at 200 degrees C for 10 h had the greatest catalytic activity for methanol electro-oxidation among the PtRu/C catalysts treated under various atmospheres and temperatures. Copyright (C) 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

Abstract  Carbon supported Pt-Ru catalysts were prepared by multiple cycles of potentiostatic pulses from aqueous diluted chloroplatinic acid and ruthenium chloride solutions in the presence of ethanol or ethylene glycol at pH 2 and 5. SEM images showed that the metallic deposit prepared at pH 2 consisted of large irregular agglomerates, whereas smaller globular particles were obtained at pH 5. In addition, the average particle size was considerably decreased in the presence of the stabilizers. The supported Pt-Ru alloys were tested as catalysts for methanol electro-oxidation in acid media. Electrocatalytic activity measurements indicated that the most active electrode was obtained with ethylene glycol as additive at pH 5. (C) 2011 Elsevier B.V. All rights reserved.

Abstract  Herein we report the covalent functionalization of multiwall carbon nanotubes by grafting sulfanilic acid and their dispersion into sulfonated poly(ether ether ketone). The nanocomposites were explored as an option for tuning the proton and electron conductivity, swelling, water and alcohol permeability aiming at nanostructured membranes and electrodes for application in alcohol or hydrogen fuel cells and other electrochemical devices. The nanocomposites were extensively characterized, by studying their physicochemical and electrochemical properties. They were processed as self-supporting films with high mechanical stability, proton conductivity of 4.47 x 10 super(-2) S cm super(-1) at 30 C and 16.8 x 10 super(-2) S cm super(-1) at 80 C and 100% humidity level, electron conductivity much higher than for the plain polymer. The methanol permeability could be reduced to 1/20, keeping water permeability at reasonable values. The ratio of bound water also increases with increasing content of sulfonated filler, helping in keeping water in the polymer in conditions of low external humidity level.

Abstract  The electrochemical behaviour of fuel cell catalysts (mesoporous Pt (MPPt), MPPtRu, MPPt modified by adsorbed Ru (MPPt/Ru) and carbon supported PtRu alloy) was studied using the thin layer flow cell differential electrochemical mass spectrometry (TLFC-DEMS) technique. The catalysts present high catalytic activity towards the methanol oxidation reaction (MOR), being the PtRu/C electrode the least active for MOR, while MPPt/Ru presents higher current densities for this reaction than MPPtRu. The results suggest that the diffusion properties obtained in the porous structure of the MP electrodes and the surface atomic arrangement in the electrode are the main reasons for the higher catalytic activity achieved. Finally, TLFC-DEMS was proved to be a powerful technique which evaluates and correlates the CO sub(2) efficiency with the catalytic activity and the porous structure of the catalysts.

Abstract  Nanodimensional powders of cubic copper ferrite are synthesized by two-steps procedure of co-precipitation of copper and iron hydroxide carbonates, followed by mechanochemical treatment. X-ray powder diffraction, Mossbauer spectroscopy and temperature-programmed reduction are used for the characterization of the obtained materials. Their catalytic behavior is tested in methanol decomposition to hydrogen and CO and total oxidation of toluene. Formation of nanosized ferrite material is registered even after one hour of milling time. It is established that the prolonging of treatment procedure decreases the dispersion of the obtained product with the appearance of Fe(2)O(3). It is demonstrated that the catalytic behavior of the samples depends not only on their initial phase composition, but on the concomitant ferrite phase transformations by the influence of the reaction medium. (C) 2011 Elsevier Inc. All rights reserved.