Traces Of Formaldehyde Research Articles

Bioconversion of fruit and sugar beet extracts by Zymomonas mobilis to ethanol and other fine chemicals

Zymomonas mobilis can grow and produce ethanol on extracts of apples, oranges, peaches, watermelons, and sugar beets without the addition of any nutrients. The best substrate for growth was watermelon extract. Strain CP4 showed the best growth kinetics on all the extracts tested, but strain NCIB 11163 failed to grow on sugar beet extracts. The highest ethanol production and yield was obtained by strain ATCC 10988 when grown on apple, orange, and watermelon extracts. Isopentanol, acetic acid, and low amounts of histidine were the major by-products produced. Traces of formaldehyde, methanol, phenol, and other higher alcohols were also detected, but H 2S was not detectable.

Electron Capture Gas Chromatographic Determination of Traces of Formaldehyde in Milk as the 2,4-Dinitrophenylhydrazone

A quantitative method is described for the determination of formaldehyde in milk by packed-column gas chromatography and electron capture detection. Aldehyde derivatization was carried out in situ with 2,4-dinitrophenylhydrazine followed by extraction and analysis using an external standard. Average recoveries of 96.3 +/- 1.6% were characteristic of the chromatographic method with an estimated detection limit of 0.026 mg/kg. The technique was applied to determination of formaldehyde in milk from cows consuming a formalin-treated feedstuff.

Catalytic methanol synthesis from carbon monoxide and water

A new process using the catalyzed reaction of formate ion to directly yield methanol from reaction of CO and H/sub 2/O in a single process is described. Of the catalysts studied, lead oxide, zinc oxide-chromium oxide, sodium metavanadate, and copper oxide-chromium oxide, the lead oxide catalyst exhibited a high selectivity for methanol production while the transition metal oxides favored hydrogen production. Small amounts of methyl formate and traces of formaldehyde were also noted when lead oxides were used as catalyst.

Detection of traces of formaldehyde in pure air by gas chromatography and helium ionization detection.

The sensitive helium ionization detector (HID) was used for the direct determination of ppm to ppb levels of formaldehyde in air. Two methods to generate formaldehyde in an air stream were evaluated. The first method utilized a paraformaldehyde permeation tube and the second utilized a motor driven syringe and a dilute solution of formaldehyde. The two methods were evaluated using gas chromatography with HID and spectrophotometry. The paraformaldehyde permeation tube generates only about 60% of the theoretical value, while the motor driven syringe was accurate for levels below 2 ppm; however, at a concentration of 13 ppm or above, oligomers or other chemical forms of CH2O are formed to decrease the concentration of gaseous CH2O produced.

The determination of traces of formaldehyde

An extensive critical review of the methods utilized to determine trace formaldehyde concentrations is presented. The methods are grouped under the physical techniques employed and are discussed with reference to interfering agents, sensitivity, reagent stability and analysis time. The applicability of the procedures is considered for routine monitoring of occupational and environmental exposure to gaseous formaldehyde.

Gas chromatographic method to determine formaldehyde traces in automobile exhaust gases

A method for the gas chromatographic determination of traces of formaldehyde is described. The formaldehyde is detected by means of a modified FID which contains a microreactor inside the jet for the hydrogenation of formaldehyde to methane. Only a slight modification to an ordinary FID is needed with no additional gas tubes and no alteration to the existing detector heater. The additional dead volume and peak broadening is negligible. The system is calibrated by means of a gas generator. The described method is used for determining the content of formaldehyde in the exhaust gases of methanol-driven cars.

Determination of traces of formaldehyde, glyoxylic and glycollic acids in acetic acid-water mixtures

Determination of traces of formaldehyde, glyoxylic and glycollic acids in acetic acid-water mixtures

A colorimetric method for the micro determination of 2-phenylphenol.

A colour reaction produced with the fungicide 2-phenylphenol is described. 2-Phenylphenol, its esters and sodium 2-phenylphenate give a pink colour with concentrated sulphuric acid and traces of formaldehyde and iron(III), which is specific for 2-phenylphenol. With 5 ml of reagents, 1 µg of these compounds produces colours that are discernible visually. In fixed conditions the reaction conforms to the Beer-Lambert law for up to 16 µg of 2-phenylphenol per 5 ml of reagents. A simple and rapid method has been evolved for its determination in disinfectant solutions containing sodium 2-phenylphenate, and in paper wrappers impregnated with 2-phenylphenol, its esters or its sodium salt. Recovery varies from 94·1 to 105·0 per cent.; the deviations remain within the limits of experimental error.

Effect of vanadium pentoxide on gas‐phase combustion. II. The methane‐oxygen system

AbstractThe slow combustion of methane in a static system, using reaction vessels coated with vanadium pentoxide, has been studied. Coating a vessel eliminated autocatalysis and retarded the oxidation, the rate of which was only measurable at above 500°. Both the overall order (5.9) and the overall activation energy (about 78 kcal/mole) were very high and the initial rate was markedly dependent on the pressure and nature of added inert gas. The products were carbon monoxide, carbon dioxide (CO/CO2 ratio about one) and water, with only traces of formaldehyde and formic acid. Packing the coated vessel virtually eliminated the pressure change, the products being almost exclusively CO2, but did not appreciably alter the rate of consumption of methane.It is concluded that the oxidation involves an unbranched chain mechanism, in which both initiation and termination occur on the walls and the propagation reactions are: the formaldehyde being rapidly oxidised at the surface so that it cannot act as a branching agent.

993. Radiation-induced decomposition of ion-exchange resins. Part I. Anion-exchange resins

Aqueous slurries of the anion-exchange resin Deacidite FF in the hydroxide form were irradiated with Co/sup 60/ gamma -rays. Severe chemical decomposition was observed at doses of up to 500 Mrad, chiefly by the destruction of strong-base functional groups resulting in the release of water-soluble aliphatic amines. Analytical techniques for the estimation of individual amines in mixtures are described, and quantitative yields of tertiary, secondary, and primary amines, and ammonia are reported. Traces of formaldehyde were detected, but peroxides and nitrites were found to be absent in the aqueous solutions associated with the irradiated resin. Total anion-exchange capacity does not fall as rapidly as strong-base quaternary capacity. It is shown that an increase in weak-base capacity is due to some conversion of quaternary groups into weak- base amine groups, caused by irradiation. Decomposition of the quaternary functional groups appears to proceed by a simple Hofmann degradation. Possible mechanisms for the production of other products are discussed. (auth)

The preparation and use of formalinized erythrocytes with attached antigens or haptens to titrate antibodies.

Summary1) Improved methods for preparation of formalinized red blood cells and a simple method using formalin to bind proteins to these cells yielding a stable, highly sensitive antigen have been described. 2) Cells prepared by these methods give agglutination patterns almost as distinct as those obtained using fresh cells, they are not agglutinated by traces of formaldehyde and are stable on storage at 3–5° C. 3) When cells were coupled with sulfanil-azo-groups a convenient and sensitive antigen for the estimation of antibody against this hapten was obtained.

Spectrophotometric determination of traces of formaldehyde

A comparative study of various colorimetric methods for determining and detecting traces of formaldehyde has been made. Chromotropic acid and 2,7-duiydroxynaphthalene were found to be the best reagents and were subjected to a thorough study. Precise and accurate methods for determining formaldehyde using either chromotropic acid or 2,7-dihydroxynaphthalene are described. The color system produced by following the standard procedure obeys Beer's law. Using chromotropic acid 0.05 μg to 2.0 μg of formaldehyde per ml can be determined quite accurately. Acrolein seems to be the only seriously interfering substance, and its interference can be much diminished by slightly modifying the standard procedure. The reagent solutions are perfectly stable.

Collection and Estimation of Traces of Formaldehyde in Air

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCollection and Estimation of Traces of Formaldehyde in AirF Goldman and Herman YagodaCite this: Ind. Eng. Chem. Anal. Ed. 1943, 15, 6, 377–378Publication Date (Print):June 1, 1943Publication History Published online1 May 2002Published inissue 1 June 1943https://doi.org/10.1021/i560118a006RIGHTS & PERMISSIONSArticle Views168Altmetric-Citations27LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (290 KB) Get e-Alerts

The photosynthesis of naturally occurring compounds. I.—The action of ultra-violet light on carbonic acid

In a preliminary paper one of us, in conjunction with Prof. Heilbron and Prof. Barker, described some observations on the action of ultra-violet light on pure aqueous solutions of carbonic acid. It was found that traces of formaldehyde were present in these solutions after insolation, provided that a stream of the gas were passed through the water during the exposure to the light. These results differed from those which had previously been recorded by Moore and Webster, who had stated that the presence of a catalyst such as colloidal ferric or uranium hydroxide was necessary. The observation by Moore and Webster that formaldehyde in aqueous solution is converted by ultra-violet light into reducing sugars was fully confirmed, and the view was put forward that the mechanism of the photosynthesis of carbohydrates from carbonic acid consisted of two stages, first, the formation of formaldehyde, and, second, the conversion of this substance into hexoses.