ALBERT — All Library Books, journals and Electronic Records Telegrafenberg

1

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Specific Detection of Nitrogen through Pyrolytic Oxidation in Organic Spot Test Analysis (1958)

Feigl, Fritz ; Amaral, J. R.

s.l. : American Chemical Society

Analytical chemistry 30 (1958), S. 1148-1150

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ISSN: 1520-6882

Source: ACS Legacy Archives

Topics: Chemistry and Pharmacology

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1021/ac60138a046

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2

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Beiträge zur organischen Tüpfelanalyse (1957)

Feigl, F. ; Amaral, J. R. ; Gentil, V.

Springer

Microchimica acta 45 (1957), S. 726-735

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ISSN: 1436-5073

Source: Springer Online Journal Archives 1860-2000

Topics: Chemistry and Pharmacology

Description / Table of Contents: Summary The following new tests are described: 1. Detection of urea based on its Hofmann degradation with alkali hypochlorite to hydrazine. The latter condenses with salicylaldehyde to yield yellow-green fluorescing salicylaldazine. 2. Detection and differentiation ofo- andp-dinitrobenzene based on the pH-dependent reduction with phenylhydrazine to yield colored quinoidal products. 3. Detection of esters of nitrous acid based on their direct reaction with the Griess reagent. 4. Detection of sulfosalicylic acid and its differentiation from salicylic acid based on the formation of nitric and nitrous esters by warming sulfosalicylic acid with alkali nitrate to 100°. 5. Detection of nitrates of organic bases through their pyrolysis to yield nitrous and nitric acid. 6. Detection of strong and intermediate strong organic acids based on the release of nitric acid when warmed with potassium nitrate to 100°. All of these tests can be accomplished within the methodology of spot test analysis and have microanalytical limits of identification.

Abstract: Résumé Description des méthodes d'identification suivantes: 1. Identification de l'urée reposant sur la formation d'hydrazine par dégradation d'Hofmann résultant du traitement par un hypochlorite alcalin. L'hydrazine condensée sur l'aldéhyde salicylique donne naissance à la salicylaldazine qui présente une fluorescence vert-jaune. 2. Identification et différenciation des o- et p-dinitrobenzènes reposant sur la réduction par la phénylhydrazine en produits quinoniques colorés, en fonction des valeurs dupH. 3. Identification d'esters de l'acide nitreux reposant sur leur réaction colorée directe sur le réactif de Griess. 4. Identification de l'acide sulfosalicylique et différenciation de l'acide salicylique reposant sur la formation des acides nitrique et nitreux par chauffage d'un nitrate alcalin avec l'acide sulfosalicylique à 100°. 5. Identification de nitrates de bases organiques reposant sur leur pyrolyse avec formation d'acides nitrique et nitreux. 6. Identification d'acides organiques forts et moyens reposant sur la mise en liberté d'acide nitrique par chauffage avec le nitrate de potassium à 100°. Toutes ces identifications peuvent être effectuées par la technique d'analyse à la touche; leurs limites de sensibilité sont microanalytiques.

Notes: Zusammenfassung Es werden folgende neue Nachweise beschrieben: 1. Nachweis von Harnstoff, beruhend auf dessen Hofmannschem Abau mit Alkalihypochlorit zu Hydrazin, das mit Salicylaldehyd zu gelbgrün fluoreszierendem Salicylaldazin kondensiert. 2. Nachweis und Unterscheidung von o- und p-Dinitrobenzol, beruhend auf der pH-abhängigen Reduktion mit Phenylhydrazin zu farbigen chinoiden Produkten. 3. Nachweis von Estern der salpetrigen Säure, beruhend auf deren unmittelbar eintretender Farbreaktion mit dem Grießschen Reagens. 4. Nachweis von Sulfosalicylsäure und deren Unterscheidung von Salicylsäure, beruhend auf der Bildung von Salpeter- und salpetriger Säure beim Erwärmen von Alkalinitrat mit Sulfosalicylsäure auf 100°. 5. Nachweis von Nitraten organischer Basen, beruhend auf deren zu Salpetersäure und salpetriger Saure führender Pyrolyse. 6. Nachweis starker und mittelstarker organischer Säuren, beruhend auf der Freilegung von Salpetersäure beim Erwärmen mit Kaliumnitrat auf 100°. Sämtliche Nachweise sind in der Arbeitsweise der Tüpfelanalyse ausführbar und besitzen mikroanalytische Erfassungsgrenzen.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/BF01236557

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3

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Vorprüfungen auf Wasser und Ammoniak abspaltende organische Verbindungen in der Tüpfelanalyse (1960)

Feigl, F. ; Amaral, J. R.

Springer

Microchimica acta 48 (1960), S. 816-820

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ISSN: 1436-5073

Source: Springer Online Journal Archives 1860-2000

Topics: Chemistry and Pharmacology

Description / Table of Contents: Summary A description is given of a preliminary test for organic compounds which yield water or ammonia on heating to 180° C. The test can be conducted as a spot test. It is based on the fact that the resulting water or ammonia brings about a pyrohydrolysis or pyroammonolysis of admixed thio-Michler's ketone or thiobarbituric acid. Hydrogen sulfide is produced and is sensitively detected by lead acetate paper. The test has been tried on 20 compounds of this kind and identification limits of 0.3 to 50μg have been found.

Abstract: Résumé On décrit une recherche préliminaire, d'exécution rapide suivant la technique des réactions à la touche, des composés organiques qui libèrent par chauffage jusqu'à 180°, de l'eau ou de l'ammoniac. Cet essai repose sur le fait que l'eau ou l'ammoniac libéré produit une pyrohydrolyse ou une pyroammoniolyse par mélange avec la thiocétone de Michler ou l'acide thiobarbiturique, ce qui engendre H2S décelable au moyen d'un papier à l'acétate de plomb d'une manière sensible. On a essayé 20 composés appropriés et obtenu les limites d'application de 0,3 à 50μg.

Notes: Zusammenfassung Eine in der Arbeitsweise der Tüpfelanalyse schnell ausführbare Vorprüfung auf organische Verbindungen, die beim Erhitzen bis 180° Wasser oder Ammoniak abspalten, wird beschrieben. Sie beruht darauf, daß abgespaltenes Wasser oder Ammoniak eine Pyrohydrolyse bzw. Pyroammonolyse von beigemengtem Thio-Michlers Keton oder Thiobarbitursäure bewirkt, wobei Schwefelwasserstoff entsteht, der durch Bleiacetatpapier empfindlich nachweisbar ist. Es wurden 20 hierhergehörige Verbindungen geprüft und Erfassungsgrenzen von 0,3 bis 50μg ermittelt.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/BF01216069

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4

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Inhibition of Methane Consumption in Forest Soils by Monoterpenes (1998)

Amaral, J. A. ; Knowles, R.

Springer

Journal of chemical ecology 24 (1998), S. 723-734

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ISSN: 1573-1561

Keywords: Methane consumption ; inhibition ; monoterpenes ; forest soils ; methanotrophs ; incubations ; soil cores ; pinene

Source: Springer Online Journal Archives 1860-2000

Topics: Biology , Chemistry and Pharmacology

Notes: Abstract Selected monoterpenes were tested for their ability to inhibit atmospheric methane consumption by three forest soils from different vegetation types and by the cultured methanotrophic strain, Methylosinus trichosporium OB3b. Subsurface soil from coniferous (Pinus banksiana), deciduous (Populus tremuloides), and mixed hardwood (Tsuga canadensis and Prunus pensylvanica) stands was used under field-moist (bulk and intact cores) and slurry conditions. Most of the hydrocarbon monoterpenes tested significantly inhibited (40–100%) methane consumption by soils at environmentally relevant levels, with (–)-α-pinene being the most effective. With the exception of β-myrcene, monoterpenes also strongly inhibited methane oxidation by Methylosinus trichosporium OB3b. Carbon dioxide production was stimulated in all of the soils by the monoterpenes tested. In one case, methane production was stimulated by (–)-α-pinene in an intact, aerobic core. Oxide and alcohol monoterpenoids stimulated methane production. Thus, monoterpenes appear to be potentially important regulators of methane consumption and carbon metabolism in forest soils.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1023/A:1022398404448

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5

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Measurement of organic-35S and organic-S in lake sediments: Methodological considerations (1993)

Amaral, J. A. ; Kelly, C. A. ; Flett, R. J.

Springer

Biogeochemistry 23 (1993), S. 61-78

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ISSN: 1573-515X

Keywords: Analysis protocols ; inorganic-S(35S) ; lake sediment ; organic-S(35S)

Source: Springer Online Journal Archives 1860-2000

Topics: Chemistry and Pharmacology , Geosciences

Notes: Abstract Three protocols for the determination of inorganic and organic sulfur fractions were tested for their suitability to estimate total indigenous organic sulfur (Sorg) and35Sorg formed from added35SO4 2− in sediments of chemically dilute lakes in the ELA. The protocols tested have all been reported in the literature. It was found that two protocols involving sequential analyses for S fractions following acid treatment gave estimates of both Sorg and35Sorg up to 87% lower than a non-sequential protocol. The low estimates were largely due to hydrolysis and solubilization of solid phase S which was then removed in a rinsing step. The non-sequential protocol, in which total reduced inorganic sulfur and total sulfur were determined on separate aliquots, is recommended as the most reliable of the three. Individual analyses in this protocol were verified for these lake sediments using a variety of S standards.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/BF00002923

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6

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Disruption of sulfur cycling and acid neutralization in lakes at low pH (1995)

Kelly, C. A. ; Amaral, J. A. ; Turner, M. A. ; [et al.]

Springer

Biogeochemistry 28 (1995), S. 115-130

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ISSN: 1573-515X

Keywords: acidification ; alkalinity generation ; metaphyton ; sulfur ; sulfate reduction

Source: Springer Online Journal Archives 1860-2000

Topics: Chemistry and Pharmacology , Geosciences

Notes: Abstract Experimental acidification of a softwater lake to below pH 5 fundamentally changed the sulfur cycle and lowered internal alkalinity generation (IAG). Prior to reaching pH 4.5, the balance of sulfur reduction and oxidation reactions within the lake was in favour of reduction, and the lake was a net sink for sulfate. In the four years at pH 4.5 the balance of reduction and oxidation reactions was in favour of oxidation, and there was a net production of sulfate (SO4 2−) within the lake. Evidence indicating a decrease in net SO4 2− reduction at pH 4.5 was also obtained in an anthropogenically acidified lake that had been acidified for many decades. In both lakes, the decrease in net SO4 2− reduction appeared to be linked not to a simple inhibition of SO4 2− reduction but rather to changes in benthic ecosystem structure, especially the development of metaphytic filamentous green algae, which altered the balance between SO4 2− reduction and sulfur oxidation. At pH's above 4.5, net SO4 2− reduction was the major contributor to IAG in the experimental lake, as it is in many previously studied lakes at pH 5 and above. At pH 4.5, the change in net annual SO4 2− reduction (a decrease of 110%) resulted in a 38% decrease in total IAG. Because of the important role of net SO4 2− reduction in acid neutralization in softwater lakes, models for predicting acidification and recovery of lakes may need to be modified for lakes acidified to pH 〈5.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/BF02180680

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