Role Of Formic Acid Research Articles

Comprehensive evaluation of matrix effect in the detection of Zn, Cd, Ni, Cu, Cr and Pb by solution cathode glow discharge optical emission spectrometry

Herein, the effect of different salt matrices on the signals of Zn, Cd, Ni, Cu, Cr, and Pb using solution cathode glow discharge optical emission spectrometry (SCGD-OES), was discussed at length. The cation interference test covered sodium, potassium, magnesium and calcium ions, while the anion interference test covered chloride and sulfate ions. Overall, the order of interference levels for the four cations was: Na+≈K+>Mg2+≈Ca2+. The emission of most elements was inhibited at Na+/K+/Mg2+/Ca2+ concentration exceeding 200 mg L-1. The impact of the two anions is not measurably different and almost no interference occurred when anion content reaching 200 mg L-1. The spectral interference caused by Na+ and K+ was also much greater than that of Mg2+ and Ca2+, which was reflected in the diminution of spectral bands of the two main molecules (OH and N2). The role of formic acid (HCOOH) has been reassessed at a salinity of 200 mg L-1 Na+. HCOOH was found to play a positive role on volatile species forming metals such as Pb, regardless of the presence of sodium salts. For elements (Cr) that are hard to evaporate and stimulate, HCOOH exhibited a strong inhibitory effect, possibly due to exacerbating the deterioration of the excitation state. For other transition metal elements in the fourth period, e.g., Zn, HCOOH demonstrated minor effects.

Aeromonas veroniidetection in Egyptian fish farms with summer tilapia mortality outbreaks and the role of formic acid in limiting its spread

From 45 private fish farms, 641 tilapia samples were collected, which suffered from tilapia summer mortality outbreaks at different localities. The findings of the conventional test and 16S rRNA gene sequence recognition indicated that the isolated bacterium from the examined farms is Aeromonas veronii. A 15-day feeding trial was conducted to determine the effects of formic acid (FA) on biochemical parameters, immunological status, cortisol levels and total gut bacterial population of A. veronii-challenged tilapia. Fish were divided into five groups. The first and second groups served as control-negative and control-positive groups, which were intraperitoneally injected with 0.2-ml sterilized tryptic soy broth and A. veronii (4.3 × 106), respectively, and both were fed with a basal diet. Groups 3–5 were intraperitoneally injected with 0.2-ml A. veronii (4.3 × 106), fed a basal diet until clinical signs appeared and fed on a medicated diet containing florfenicol 15 mg/kg fish body weight and 0.5% and 1% FA respectively. The results suggest that including 1% FA in the diet lowered mortality and relieved the pathogenic effects of A. veronii on the general health status of tilapia fish.

The Role of Formic Acid as Secondary Dopant and Solvent for Poly(O-Toluidine) Intrinsically Doped with Camphor Sulfonic Acid

The role of formic acid as Secondary Dopant for Poly (O-toluidine) Intrinsically Doped with Camphor Sulfonic-Acid (POT-CSA) nanoparticles were prepared by chemical polymerization had been studied. Spin coating and casting method have been used to deposit good adhesion and uniform thin films of (POT-CSA) on a glass substrates at room temperature. the properties of (POT-CSA) nanoparticles which examined by FTIR, SEM, AFM, XRD, I-V characteristics and UV-VIS. FTIR studies show the several bending and stretching modes of POT. XRD examination demonstrated that NPS. has a semi-crystalline pattern . The synthesized film well covered by the nanoparticles over the entire substrate surface, exhibits uniform, porous, and spherical granular surface morphology, A narrow size distribution is observed and the average size of particles about 80 nm. The band gap (Eg) has been determined which is equal to 3.1 ev. The room temperature conductivity of POT-CSA was 3 * 10-1 S.cm-1,which increases with increasing temperature. Electrical conductivity enhances up to three order after the secondary doping process. Keywords: POT-Chemical polymerization-Conducting polymer-SEM-AFM

Promotion of auxin- and gibberellin-induced elongation of epicotyl segments of Vigna angularis by short-chain carboxylic acids.

Pollen tube growth is inhibited and promoted by long- and short-chain carboxylic acids, respectively, but is not affected by formic acid. For auxin- and gibberellin-induced elongation of in vitro cultured epicotyl segments of adzuki bean (Vigna angularis), a series of carboxylic acids showed similar effects as that on pollen tube growth except that formic acid showed the strongest promotive effect. The effects of formic acid and GA3 on IAA-induced elongation were additive and both were strongly inhibited by inhibitors of cellulose synthesis (coumarin) and microtubule formation (colchicine). Formic acid, possibly by incorporation into the segments, prolonged the promotion by IAA and GA3 of the elongation of epicotyl segments. Based on these results and later advances in our understanding of metabolism and the role of formic acid in protecting against oxidative stress, a possible role of formic acid on stem elongation is discussed.

Metal-free abatement of nitrate contaminant from water using a conducting polymer

A mechanism for the reduction of aqueous nitrate with metal-free polypyrrole (PPy) is proposed. The activity and selectivity of the polymer has been compared to those of metal catalysts supported on polypyrrole, activated carbon or titania (TiO2). The role of formic acid (FA) and hydrogen (H2) as reductants, and carbon dioxide (CO2) as buffer of the aqueous nitrate solution is discussed and compared to the performance of PPy by itself. The ion-exchange and the redox properties of PPy are strongly affected by the oxidation state of the nitrogen moieties in the polymeric chain. This is determined by the oxidant/dopant used in the polymer synthesis (FeCl3 or K2S2O8). The degree of oxidation of PPy can also be modified by a plasma treatment of the polymer, which determines the ability of PPy to carry out the reduction of nitrate by the electrons provided by the polymeric chain and also affects the selectivity of the nitrate reduction.

The Counter-Roll in Science

A controlled experiment, everyone learns early in school, is the hallmark of good science. But what, exactly, is the hallmark of a controlled experiment? For many people, a controlled experiment is, straightforwardly, one “controlled” by the scientist. If you can “control” the variables and produce a predicted result (based on your hypothesis), then you seem to have proved cause and effect. Scientific credibility seems to emerge from the power of demonstration and technology. However, this widespread view of the core meaning of control in science – this month's Sacred Bovine – is mistaken (Boring, 1954, 1969). It thus fosters a misleading impression of what makes scientific claims reliable. Here, I journey through the history of the term control and show how the concept contributes to the distinctive nature of scientific reasoning. The origin of the modern term control may seem surprising. Yet it is also informative. It comes from the French contre-rolle , translated as “counter-roll.” No one uses counter-rolls today. But historically (beginning at least by the 12th century), royal household expenditures were documented on paper rolls. Later, rolls recorded other business, trade, and tax accounts (Figure 1). In some cases, the transactions were recorded on two rolls simultaneously. The duplicate roll – the counter -roll – was kept independently by a trusted officer. The copy could later be consulted when auditing the accounts, allowing one to detect any illicit tampering with the original records. Basically, the counter-roll was a parallel reference copy for comparison, a method to identify and thereby limit errors. The method helped to guarantee reliability in accounting (see Hoskin & Macve, 1994, p. 76). Eventually, the person who managed the counter-roll became known as the comptroller – a term still used today for someone who manages and monitors the finances of a business …

Corrigendum: Corrigendum: Effect of Solvent, Role of Formic Acid and Rh/C Catalyst for the Efficient Liquefaction of Lignin

Corrigendum: Corrigendum: Effect of Solvent, Role of Formic Acid and Rh/C Catalyst for the Efficient Liquefaction of Lignin

Effect of Solvent, Role of Formic Acid and Rh/C Catalyst for the Efficient Liquefaction of Lignin

AbstractWe demonstrate highly efficient liquefaction of alkali lignin with a very high yield of THF‐soluble bio‐oil (91.5 wt %) using formic acid (FA) and Rh/C catalyst under relatively mild reaction conditions (250 °C, 6 h) in EtOH−H2O co‐solvent system. The monomeric products are identified in which alkyl guaiacols accounts for the main proportion. The role of FA was not only used as a liquid‐phase in‐situ hydrogen source but also acts as organic acid which can catalyze the hydrolysis reaction of −C−O−C ether bonds of lignin. Moreover, in the present study, the role of Rh/C and FA is demonstrated for the liquefaction of lignin. The replacement of pure H2 gas by the liquid‐phase FA (hydrogen source) can effectively prevent the char formation. The utilization of Rh/C catalyst helps for the conversion of alkenyl guaiacols to alkyl guaiacols suggesting the hydrogenation of phenolic monomers and further cleavage by hydrogenation results in the formation of bio‐oil with lower molecular weight (Mn=466 g mol−1) as well as lower O/C ratio (0.26).

Hybrid Copper-Silver Conductive Tracks for Enhanced Oxidation Resistance under Flash Light Sintering.

We developed a simple method to prepare hybrid copper-silver conductive tracks under flash light sintering. The developed metal nanoparticle-based ink is convenient because its preparation process is free of any tedious washing steps. The inks were composed of commercially available copper nanoparticles which were mixed with formic acid, silver nitrate, and diethylene glycol. The role of formic acid is to remove the native copper oxide layer on the surface of the copper nanoparticles. In this way, it facilitates the formation of a silver outer shell on the surface of the copper nanoparticles through a galvanic replacement. In the presence of formic acid, the copper nanoparticles formed copper formate, which was present in the unsintered tracks. However, under illumination by a xenon flash light, the copper formate was then converted to copper. Moreover, the resistance of the copper-only films increased by 6 orders of magnitude when oxidized at high temperatures (∼220 °C). However, addition of silver nitrate to the inks suppressed the oxidation of the hybrid copper-silver films, and the resistance changes in these inks at high temperatures were greatly reduced. In addition, the hybrid inks proved to be advantageous for use in electrical circuits as they demonstrated a stable electrical conductivity after exposure to ambient air at 180 °C.

The roles of formic acid and levulinic acid on the formation and growth of carbonaceous spheres by hydrothermal carbonization

The roles of formic acid and levulinic acid on the formation and growth of carbonaceous spheres.

New Insights into the Formic Acid Oxidation Mechanism on Platinum Electrodes

In the formic acid oxidation reaction only two electrons are exchanged. Despite the apparent simplicity of this reaction, the oxidation mechanism is still a subject of debate. The major issue is the role of formic acid, solution formate and adsorbed formate in the oxidation mechanism. In order to shed light into this issue, formic acid oxidation on platinum single crystal electrodes has been studied to determine the effects of pH and specific anion adsorption in the oxidation mechanism. It has been found that the solution pH has an important effect in the oxidation currents. As has been already observed for polycrystalline electrodes [1], currents are proportional to the solution pH. Thus, it can be proposed that the active species in the oxidation mechanism is formate. On the other hand, the specific adsorption of sulfate on the Pt(111) electrode has a catalytic effect on the oxidation since the onset potential is displaced towards more negative values. This unexpected result indicates that the adsorbed anions have an important role in the oxidation mechanism as DFT calculations suggest [2]. In order to get further insight into the oxidation mechanism, activation energies have been calculated, both for the route through the active intermediate and for the route through CO. The activation energy of the process diminishes in the presence of adsorbed sulfate, which confirms the active participation of the adsorbed anion in the oxidation mechanism. Using previous data obtained with fast voltammetry [3], an oxidation mechanism is proposed for the direct route. In this mechanism, the oxidation through the active intermediate route requires an adsorbed anion (formate or sulfate) and a free platinum site where a solution formate species can bond. The currents calculated with this mechanism are compared with the experimental currents. An excellent agreement is found between both results, which supports the validity of the proposed oxidation mechanism.

Upgrading Heavy Oil by Catalytic Aquathermolysis Using Formic Acid as Hydrogen Donor

The aquathermolysis (AqTh) of Liaohe heavy crude oil (HCO) in a 300ml autoclave is investigated with an oil soluble catalyst and formic acid as hydrogen donor at 280°C for 24h in N2 atmosphere，with initial pressure 8.1 MPa. The catalyst is a green viscous liquid of nD=1.4737 and made from naphthenic acid and nickel sulfate. The viscosity of HCO is temperature sensitive, being of 3716 mPa·s at 50°C and shear rate 44.1 s-1.The plain catalytic AqTh of HCO leads to a percentage viscosity reduction(PVR) of 64.69%，to an increase in saturates and aromatics contents from 24.32% and 36.89% to 26.12% and 38.08%, and to a decrease in resins, asphaltenes, and sulfur contents from 30.27%，8.52%, and 0.5650% to 28.27%,7.53%,and 0.3365%, respectively; when formic acid is introduced at dosage of 1~7% HCO mass, the PVR is continuously raised to 69.16~87.02%, the saturates and aromatics contents increased to 27.73~31.12% and 39.68~41.26% and the resins, asphaltenes, and sulfur contents decreased to 26.29~24.12%, 6.66~3.50% and 0.3095~0.0742%,respectively. The IR-spectrometry shows that decarboxylation is conducted and number of aromatic rings is lessened in hydrogen donor catalytic AqTh. The role of formic acid and the functioning mechanisms involved inatalytic AqTh of HCO are discussed.

Formation of formic acid and cyclohexyl formate in oxidation of cyclohexane

The consistency of the suggested mechanisms of formic acid formation with the composition of products formed in the industrial process of cyclohexane oxidation was examined. The role of formic acid in the formation of cyclohexyl esters of mono-and dicarboxylic acids was elucidated.

Effects of organic hole scavengers on the photocatalytic reduction of selenium anions

The photocatalytic reduction of selenium anions, selenate (Se(VI)) and selenite (Se(IV)) to elemental selenium (Se) over UV-illuminated TiO2 was performed using formic acid, acetic acid, methanol, ethanol, sucrose and salicylic acid as the organic hole scavengers. Photoreduction was only observed in the presence of formic acid, methanol or ethanol. The fastest rate of Se ions photoreduction was observed in the presence of formic acid followed by methanol and ethanol. This was attributed to the ability of formate ions to adsorb onto TiO2 in the presence of Se ions, its fast mineralisation rate and its ability to form reducing radicals quickly. For the methanol and ethanol systems, these two organic compounds could not compete with Se ions for the TiO2 surface and were not easily mineralised. The photocatalytic reduction of Se ions observed in the presence of these two organic compounds was attributed to their ability to form reducing radicals. When formic acid was used, optimum pH values at pH 3.5 and 4.0 was encountered for the Se(VI) and Se(IV) photoreduction, respectively. When methanol and ethanol were used as the hole scavenger in the pH range of 2.2–4.0, the greatest extent of Se ions photoreduction was encountered at pH 2.2. This suggests the different role of formic acid and methanol/ethanol in the photoreduction of Se ions.

The Role of Formic Acid and Methanol on Speciation Rate and Quality in the Electrodeposition of Chromium from Trivalent Electrolytes

SummaryA successful enhancement of both the quality and the deposition rate has been obtained by the addition of some quantities of formic acid and methanol. The results were obtained by using very conventional conditions such as 25°C, no pH adjustment, low current density and very gentle agitation. An excellent quality of deposit with a deposition rate of 50–100 μm/hr was obtained. And sustained deposition up to ≈ 200 μm/hr was achieved with prolonged electrolysis.The change in the chemical speciation of the electrolyte was studied by using Ion-exchange chromatography. A separation and identification of the various species, formed as the bath was aged with time, was obtained. The chromium concentration of each band was measured using the ICP spectrometer, monitoring the change in the concentration of the species with ageing. U. V. visible spectrometry was also used to confirm identification of the species.A clear correlation has been established between loss of deposition rate and the formation of higher oligomeric chromium (III) species. The role of methanol and formic acid in inhibiting this effect is discussed.

Phosphorus pentoxide promotion of iridium-catalysed rearrangement of methyl formate in the absence of initial CO pressure

The possible roles of formic acid as an effective solvent for the iridium-catalysed conversion of methyl formate to acetic acid in the absence of initial carbon monoxide pressure are elucidated. Based on the finding, a strong acid anhydride, such as phosphorus pentoxide, which can maintain the concentration of methyl formate as high as possible compared to that of methyl acetate, is proposed as and proved to be a highly effective promoter for the reaction.

Growth of Lactobacillus bulgaricus in Milk. 1. Cell Elongation and the Role of Formic Acid in Boiled Milk

An abnormal elongation of cells occurred when Lactobacillus bulgaricus B5b was cultivated in milk heated at 100°C for 15min. Nuclear staining revealed that the elongated cells were multinucleate, and septum staining indicated that the septum had not yet formed. Similar cell elongation was confirmed using other strains of L. bulgaricus.Extent of cell elongation varied with strains and heating conditions of milk; severe heating shortened the cell length. This cell elongation was not observed in autoclaved milk (121°C, 15min), milk containing added formic acid and heated to 100°C for 15min, and in mixed culture with Streptococcus thermophilus. The formate added to the milk was incorporated into purines of ribonucleic acid and deoxyribonucleic acid of the cells. Addition of formic acid or adenine stimulated ribonucleic acid synthesis in the cells cultivated in milk heated to 100°C for 15min. The cell elongation was always accompanied by a remarkable depression of ribonucleic acid synthesis.Lactobacillus bulgaricus cells grown in milk heated to 100°C for 15min are not able to produce adequate amounts of formic acid required for synthesis of purines de novo.

Methanol poisoning in human subjects: Role for formic acid accumulation in the metabolic acidosis

Whereas a great deal of information is available on the etiology of methanol poisoning in the monkey, very little study has been made in human subjects. The role of formic acid in methanol toxicity in human subjects has not been established. Two patients have been studied who have presented with the characteristics of methanol poisoning—metabolic acidosis and ocular toxicity. This has made possible a confirmation of the role of formate in the toxic syndrome. Acidosis was very severe in both cases with arterial pH values of about 6.9 and plasma bicarbonate concentrations of 3 meq/liter. A sensitive and specific assay was used to measure formic acid levels in blood and other fluids. Formate accumulation was marked with initial blood levels ranging from 11.1 to 26.0 meq/liter. Decreases in blood bicarbonate concentrations of similar magnitude coincided with the increase in formate. Thus, accumulation of formic acid plays a major part in the acidosis observed in human subjects poisoned with methanol, as has been demonstrated in monkeys. Treatment, involving bicarbonate administration, ethanol infusion and hemodialysis, rapidly decreased formate levels in the blood to control values. Methanol concentrations were reduced but to lesser extent than that of formate. Despite the reduction in formate and methanol concentrations in both cases, the treatment was successful in only one of the two patients.

3150. Methanol toxicity: the search for a model animal: McMartin, K. E., Makar, A. B., Martin, A. G., Palese M. & Tephly, T. R. (1975). Methanol poisoning I. The role of formic acid in the development of metabolic acidosis in the monkey and the reversal by 4-methylpyrazole. Biochem. Med.13, 319

3150. Methanol toxicity: the search for a model animal: McMartin, K. E., Makar, A. B., Martin, A. G., Palese M. & Tephly, T. R. (1975). Methanol poisoning I. The role of formic acid in the development of metabolic acidosis in the monkey and the reversal by 4-methylpyrazole. Biochem. Med.13, 319

Methanol poisoning I. The role of formic acid in the development of metabolic acidosis in the monkey and the reversal by 4-methylpyrazole

The administration of methanol (3 g/kg) to rhesus and pigtail monkeys produced signs and symptoms similar to those described for methanol poisoning in man. These were a mild central nervous system depression, a latent period of 8–12 hr when no signs were observed, followed by a severe metabolic acidosis leading to coma and death 12–33 hr after the initial administration. The gradual development of metabolic acidosis coincided with the accumulation of formic acid in the blood, and the decrease of bicarbonate in the plasma. There was an increase in the anion gap during the period of metabolic acidosis, and formic acid concentration accounted for about one-half of the increase observed. Therefore, formic acid was a major, but not the only, determinant of the metabolic acidosis. Administration of 4-methylpyrazole (50 mg/kg), a potent inhibitor of monkey hepatic alcohol dehydrogenase, produced a 75% inhibition of the rate of [ 14C]methanol metabolism to 14CO 2 in the monkey. During the first 36 hr following the administration of 4-methylpyrazole and methanol, no metabolic acidosis developed, no formate accumulated in the blood, and no signs of toxicity were observed. After a single dose of 4-methylpyrazole and methanol, the toxic syndrome was delayed by about 36 hr in the monkey, after which time the onset of metabolic acidosis and the accumulation of formic in blood was noted. The use of the monkey as a model for the study of methanol poisoning is presented, and the possible use of 4-methylpyrazole in the treatment of methanol poisoning is implicit.