Devarda's Alloy Research Articles

Steam distillation methods for determination of ammonium, nitrate and nitrite

Steam distillation methods of determining ammonium, nitrate, and nitrite in the presence of alkali-labile organic nitrogen compounds are described. They involve the use of magnesium oxide for distillation of ammonium, ball-milled Devarda alloy for reduction of nitrate and nitrite to ammonium, and sulfamic acid for destruction of nitrite. The methods are rapid, accurate, and precise, and they permit nitrogen isotope-ratio analysis of ammonium, nitrate, and nitrite in tracer studies using 15 N-enriched compounds. They give quantitative recovery of ammonium, nitrate and nitrite added to soil and plant extracts, and appear suitable for analysis of biological materials.

Determination of nitrate in fermentation media by a modification of the nitron method

AbstractA method is described which is suitable for the determination of nitrate in complex culture media. Nitrate is first precipitated as nitron nitrate and the precipitate reduced to ammonia by Devarda's alloy. The ammonia is distilled and determined colorimetrically by means of Nessler's reagent. Recoveries are in the range 98–102% for amounts of nitrate between 0.1 and 1.0 mg. per ml. of solution.

Tüpfelreaktionen von rhodanid durch reduktive aufspaltung: Ein beitrag zur chemie der spezifischen, selektiven und empfindlichen reaktionen

In the reduction of thiocyanates in acidic or alkaline solution by Devarda alloy, respectively hydrogen sulfide or a mixture of methylamine and ammonia is formed. The identification of these reaction products in the vapor phase allows a fairly selective test for thiocyanates by means of spot test methods. Limits of identification of 0.12 μg resp. 0.2mg thiocyanate were obtained.

Spot Tests Based on Redox Reactions with Devarda's Alloy and Raney Alloy

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSpot Tests Based on Redox Reactions with Devarda's Alloy and Raney AlloyFritz. FeiglCite this: Anal. Chem. 1961, 33, 8, 1118–1121Publication Date (Print):July 1, 1961Publication History Published online1 May 2002Published inissue 1 July 1961https://doi.org/10.1021/ac60176a018RIGHTS & PERMISSIONSArticle Views81Altmetric-Citations11LEARN 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 (582 KB) Get e-Alerts Get e-Alerts

Untersuchungen zur Geochemie des Stickstoffs

Two methods for the determination of combined nitrogen in rocks and minerals are described: 1. (1) Determination of total combined nitrogen by decomposition of the rock by fusion with NaOH in a closed system, and solution of the melt in water. By this method of decomposition a part of the existing NH 3 is oxidized to NO 3 therefore it is impossible to determine NH 3 and NO 3 separately. The NO 3 is reduced by Devarda's alloy to NH 3, which is distilled off with the primary NH 3, adsorbed in a standard acid and determined colorimetrically by the Nessler method. 2. (2) Determination of NH 3-N and NO 3-N separately by decomposition of the sample with hydrofluoric acid at 90°C in a closed polyethylene-bottle, neutralization of the acid with NaOH and distillation and determination of the NH 3 as under (1). After that determination of NO 3 as NH 3 by reduction by Devarda's alloy. In both methods the NH 3 can be determined with an accuracy of 10%, for amounts less than 10 ± 1 g/ton. The error of the NO 3 determination is 25% and the sensitivity is 5 g/ton. In 400 rock and mineral samples NH 3-N and NO 3-N were determined mainly by the second method. Besides this the water-soluble nitrogen was determined in all magmatic rocks and minerals. The results show that nearly all magmatic rocks contain NH 3-N, ranging between 5 and 50 g/ton, of which approximately one-half is water-soluble. There exists no characteristic difference between the different groups of rocks. Some rocks, which are not fully degassed, contain more NH 3 than the average, up to 150 g/ton. The average content of magmatic rocks is 20 g NH 3-N/ton. NO 3-N was not found. The distribution of the NH 3-N between the different minerals of a rock was determined by separation of some granites, granodiorites and a basalt into their mineral constituents. Muscovite and biotite are richest in NH 3-N (average of 60 and 33 g/ton), feldspars contain less (20 g/ton), and quartz least (13 g/ton). Late-magmatic minerals such as zeolites are higher in NH 3-N than the rocks in which they occur, and the same is true for hydrothermally altered minerals (chloritization and sericitization). The distribution of the NH 3-N between the different magmatic rocks and minerals and the presence of water-insoluble NH 3-N in nearly all magmatic rocks leads to the conclusion that the NH 3-N is of primary magmatic origin. The existence of nitrides in rocks is discussed and is considered to be improbable. The NH 3-N content of sedimentary rocks is higher than in magmatic rocks. Clays and clayslates contain in the average 580 g NH 3-N/ton, sandstones 135 g/ton and limestones 70 g/ton. Several series of sediments show that the NH 3-content is dependent on the content of micas and clayminerals. NO 3-N was found in minute amounts (5–20 g/ton) in surface sediments, some saline clays and in limestones. Average clays and sandstones contain no NO 3-N. Metamorphic sediments contain much less NH 3-N than the unaltered rocks. The NH 3-N content of paragneisses and orthogneisses is variable, but in the average paragneisses contain more NH 3-N than orthogneisses. Finally the average NH 3-N content of the lithosphere is estimated.

Argentometric titrations by means of redox indication—III: Determination of nitrate ions and nitro compounds

A new method for the determination of nitrate has been worked out. ( a) Nitrate ions can be reduced to ammonia in acidic medium by means of ferrum reductum in the presence of nickel sulphate. Ammonia can be precipitated in acidic medium as ammonium tetraphenylboron. After filtering and washing, the precipitate can be dissolved in acetone and the solution can be titrated with silver nitrate with Variamin Blue acetate as indicator. ( b) Nitrate ions can be reduced in alkaline medium with Devarda's alloy, the ammonia being distilled and titrated as described above. This method has been applied to the determination of nitrates accompanied by organic material, and of nitrozo, azo and diazo compounds.

トリメチルアミン及びトリメチルアミンオキシドの定量法について

The extraction of trimethylamine (TMA) with toluene was found to be affected by temperature, sorts of alkali and number of shaking times, as shown in Fig. 1 and Table 1, whereas the color development of TMA with picric acid was not influenced by temperature. From these observations, the extraction procedure was modified to be carried out at a definite temperature (30°C). In an incubator, test solutions, reagents and funnels were previously warmed before extraction and the funnels shaken 60 times were again left for 5 minutes in it before the separation of toluene layer. In the second place, the same volume of 25% potassium hydroxide solution was adopted instead of the original 50% potassium carbonate solution, which was confirmed to be not suitable for the TMA solution resulting from the reduction of trimethylamine oxide (TMO) with Devarda's alloy and hydrochloric acid. Figures in Table 2 indicate that some constituents of the alloy may disturb the extraction of TMA in the case of potassium carbonate, but not in the case of the hydroxide. This agrees well with the fact that the carbonate forms white colloidal precipitates, perhaps carbonates of Al and Zn, in the aliqout of the heated reducing mixture, and the precipitates were suspected to adsorb or occlude TMA. The hydroxide does not give such precipitates. The modification above-mentioned facilitated the determination of the smaller amount of TMO and the modified method gave over 97% recovery down to 0.025mg N which is far lower than 0.4mg N in the DYER method (Fig. 2). The recovery of TMO added to carp muscle extracts was also satisfactory (Table 3).

Studies on fluidization. II—heat transfer

In a small scale apparatus the heat transfer coefficient to the cylindrical wall of a fluidizing bed (“dense phase”) was measured under strongly varying conditions of gas and solids. The solids used were closely sized samples as well as mixtures of different sizes of carborundum, ironoxide (Fe 3O 4), coke, lead, Devarda's alloy, and fly ash. The gases used were air, mixtures of nitrogen and hydrogen, carbon dioxide, argon, town's gas and methane. For a correlation of the measuring result use is made of a system of dimensionless numbers that may be considered as a complete representation of all variables which may be expected to influence the value of the transfer coefficient. The gas rate is characterized by the reduced mass velocity G/ G 0 where G 0 is the mass velocity at which fluidization starts. A correlation based on this variable proves to be successful for Re < 5 and can be written as: ▪ when ψ( G/G 0) = 0,028( G/G 0) 0.45 for 2 < G/G 0 < 20; a larger region (1 < G/G 0 < 30) can be covered by ▪ With the aid of the generalized shape factor B introduced in Part I of this study, the above mentioned relationship can be transformed into a correlation restricted to the region 2 < G/G 0 < 20. This can be written as ▪ where for Re < 5, χ ( B Re) = 0,58 ( B Re) 0.45.

THE DETERMINATION OF NITRATES IN COLORED SOIL EXTRACTS

In highly colored soil extracts, it was found impossible to determine nitrates directly by the phenoldisulphonic acid color reaction. Attempts to remove the coloring matter by oxidation or absorption were not successful. The most satisfactory method was found to be reduction of the nitrate to ammonia with Devarda's alloy in 0.1 N sodium hydroxide solution in the cold after the removal by steam distillation, of any ammonia that might be present in the extract. The ammonia formed from the nitrate was steam distilled into 0.01 N hydrochloric acid solution and determined colorimetrically by Nessler's reagent using a Klett–Summerson photoelectric colorimeter. The recovery of nitrates from the colored solutions and from standards was satisfactory. The aliquot taken for the determination should contain not more than 0.125 mgm. nitrogen as nitrate.

Effect of Silica on the Quantitative Reduction of Nitrates with Devarda Alloy

Effect of Silica on the Quantitative Reduction of Nitrates with Devarda Alloy

The determination of nitrates in plant materials

1. The Valmari-Devarda method of estimating nitrates (i.e.distillation with magnesium oxide and Devarda's alloy) is unsatisfactory in presence of organic matter. Attempts to make it quantitative under these conditions by modifications of alkali and temperature proved unsuccessful.2. Two new methods for the estimation of nitrate in plant juices are described. The first depends on the use of Devarda's alloy in cold weakly alkaline solutions, the second on the reducing power of titanous hydroxide, under conditions suitable for use with plant products.

Quantitative Chemical Analysis: Adapted for Use in the Laboratories of Colleges, of Technical Institutes, and of Analysts

“CLOWES AND COLEMAN” is so well known that it is only necessary to state that the new edition will be found as useful as those of the past. There are a few points which might be suggested in the way of improvement. The method of weighing by vibrations is so superior to the zero method that it is now generally used, but the statement that “consecutive swings to the right and to the left must finally be equal in extent” (p. 9) is not satisfactory. The correct method should be explained. The methods used in the calibration of volumetric apparatus are also approximate only, but are suitable for elementary students. The analysis of industrial products is a special and valuable feature, but some of the newer methods (e.g. the reduction of nitrates by Devarda's alloy) are not given. The range of exercises is extensive, and the book may be recommended to students and analysts as an excellent introductory treatise and work of reference.

A Text-book of Quantitative Chemical Analysis

THE first edition of this book was published in 1913, and the appearance of the fourth edition less than ten years later shows that it has been found in practice a most useful guide to students. The present volume should provide a sound course of quantitative analysis for students in universities and technical schools. It is very practical, and gives many hints to students which will save the time of teachers. The reduction method with Devarda's alloy might have been given for the estimation of nitrates, instead of the one with reduced iron, which is less satisfactory. In the description of the Lunge nitrometer no mention is made of the important correction for the solubility of nitric oxide in the acid. The directions for the preparation of cupferron reagent on p. 410 will be found useful, as the price charged for this substance is almost prohibitive.

Estimation of nitric nitrogen and total nitrogen in plant tissue extracts

Several methods for estimating nitrates by reduction to ammonia were examined. The error involved in the use of acid reducing agents in presence of amino groups was emphasised.A method based on the use of Devarda's alloy and magnesia is recommended.In the estimation of nitrates in plant extracts, etc., by this method an equal volume of rectified spirit is first added to the solution to precipitate colloidal matter. The precipitate is filtered off and an aliquot part of the filtrate containing the equivalent in nitrate nitrogen of about 0.1 gm. of KNO3 is distilled with steam for 45 minutes with 1 gm. of Devarda's alloy and ½ gm. of freshly ignited magnesia. A blank determination is essential, in which the same volume of filtrate is distilled for the same length of time with ½ gm. of magnesia.In Kjeldahl estimations in presence of nitrates, where the separate estimation of nitrates is not required, 2 c.c. of 25 per cent. NaOH may be substituted for the magnesia. Relatively this is very much less soda than Devarda recommends. The mixture in this case may be distilled directly for half-an-hour. The nitrates are thus reduced and the ammonia produced is collected before beginning the digestion with sulphuric acid.This work was carried out under the supervision of Mr F. W. Foreman to whom the author's best thanks are due for much valuable criticism and advice.