Determination of Total Nitrogen in Fertilizers

1965 ◽  
Vol 48 (2) ◽  
pp. 401-406
Author(s):  
H A Davis ◽  
W E Urban
Keyword(s):  
Nickel Catalyst ◽  
Raney Nickel ◽  
Total Nitrogen ◽  
Official Method ◽  
Chromium Powder ◽  
Powder Method ◽  
Raney Nickel Catalyst ◽  
Catalyst Powder ◽  
Iron Chromium

Abstract Five methods, AOAC 2.037, 2.039, modified reduced iron, chromium powder, and Raney nickel catalyst powder for the determination of total nitrogen in fertilizers, were submitted to collaborators for study. Twelve laboratories participated and completed the work. No one method was “best.” The modified reduced iron, chromium powder, and Raney nickel catalyst powder methods gave essentially equal results, but the chromium powder method is favored for case of operation and time required. However, if considerable organic matter and nitrate are present in a sample, satisfactory results may not be obtained. The analyst should select the official method best suited to the makeup of the sample. It is recommended that the chromium powder method he adopted as official, first action, and that study be continued with the modified reduced iron and Raney nickel catalyst methods, including helpful proposals in developing a method that may be applicable to all fertilizers.

How Rugged Are Our Nitrogen Methods?

1965 ◽  
Vol 48 (3) ◽  
pp. 501-507
Author(s):  
W G Burgh ◽  
J A Brabson
Keyword(s):  
Salicylic Acid ◽  
Standard Deviation ◽  
Total Nitrogen ◽  
Reduction Method ◽  
Official Method ◽  
Powder Method ◽  
Catalyst Powder ◽  
Time Of Reaction

Abstract Youden’s ruggedness test was made of two official methods and four more recent methods for the determination of total nitrogen in fertilizers containing nitrates. Among the variables tested were amounts of nitrogen and reductant, effect of chloride, and time of reaction of reductant. Official method 2.039 (reduced-iron) failed the test. In order of increasing standard deviation, the five methods that passed the test were the chromous reduction method, Raney-catalyst-powder method, official method 2.037 (salicylic acid), improved reduced-iron method, and the chromiumpowder method.

An Improved Raney Catalyst Powder Method for Determination of Nitrogen in Fertilizers

1965 ◽  
Vol 48 (6) ◽  
pp. 1111-1115
Author(s):  
W G Burch ◽  
J A Brabson
Keyword(s):  
Sulfuric Acid ◽  
Total Nitrogen ◽  
Organic Nitrogen ◽  
Nitrogen Compounds ◽  
Test Results ◽  
Powder Method ◽  
Catalyst Powder ◽  
Good Agreement

Abstract With a Raney catalyst powder containing 10% Co, 40%; Ni, and 50% Al, nitrates are reduced to ammonia in 8N sulfuric acid in 10 minutes. Neither chlorides nor organic nitrogen compounds interfere with the reduction, and the reduction passed Youden’s ruggedness test. Results of analyses of fertilizers for total nitrogen that included reduction with the powder were in good agreement with those of accepted methods.

Total Nitrogen in Fertilizers

1968 ◽  
Vol 51 (4) ◽  
pp. 851-857
Author(s):  
Paul R Rexroad ◽  
Gary F Krause
Keyword(s):  
Total Nitrogen ◽  
Collaborative Study ◽  
New Method ◽  
Official Method ◽  
Powder Method ◽  
Catalyst Powder

Abstract A three-laboratory collaborative study was made of the comprehensive nitrogen method and the new Raney catalyst powder method for total nitrogen in fertilizers. Both methods worked quite well and, with minor modifications, they should provide the basis for a broader collaborative stvidy to provide an official method for total nitrogen in fertilizer applicable to all samples. The limitations of method 2.045 are reviewed and a rephrasing of the official applications of the method is recommended. Further work is recommended toward adoption of a new method and possible deletions or change of status in current official methods.

An Unforeseen Problem in the Use of Kel-Paks

1968 ◽  
Vol 51 (6) ◽  
pp. 1290-1295
Author(s):  
T C Woodis ◽  
J A Brabson ◽  
W G Burch
Keyword(s):  
Salicylic Acid ◽  
Nicotinic Acid ◽  
Organic Compounds ◽  
Total Nitrogen ◽  
Ammoniacal Nitrogen ◽  
Powder Method ◽  
Catalyst Powder ◽  
Possible Cause ◽  
Digestion Step

Abstract In Kjeldahl methods for the determination of nitrogen in fertilizers, the digestion temperature must be above 370°C to mineralize the nitrogen in refractory organic compounds such as nicotinic acid. In total nitrogen determinations by the Raney catalyst powder method, temperatures during the digestion step were investigated as a possible cause of occasional low results. Decomposition of the polyethylene envelopes of Kel-Paks in the presence of salts of metallic reductants caused rapid fluctuations and excessive rise in temperature with consequent loss of ammoniacal nitrogen. Complete Kel-Paks can be used without difficulty in methods such as 2.044 (for nitrate-free samples) or 2.045 (salicylic acid) that do not use metallic reductants, but only the contents of the Kel-Paks without the envelopes should be used when Raney catalyst or chromium powders have been used to reduce nitrates.

Total Nitrogen Methods—Applicable to All Fertilizer Samples

1970 ◽  
Vol 53 (3) ◽  
pp. 450-456
Author(s):  
Paul R Rexroad ◽  
Gary F Krause
Keyword(s):  
Salicylic Acid ◽  
Total Nitrogen ◽  
Collaborative Study ◽  
Official Method ◽  
Chromium Powder ◽  
Powder Method ◽  
New Methods

Abstract An extensive collaborative study was conducted to evaluate a comprehensive nitrogen method and a Raney powder method for acceptance as official methods. Twenty-nine laboratories participated; 10 samples were used and the new methods were compared to the official method, 2.045 (sulfuric-salicylic acid). Evaluation of the data and overall consideration lead to the recommendation that both new methods be adopted as official. It is recommended that 2.047 (reduced iron) and 2.049 (chromium powder) be deleted as official methods.

Hydrophobic hydrogen anode with a nickel catalyst

1982 ◽  
Vol 47 (12) ◽  
pp. 3230-3235 ◽  
Author(s):  
Olga Marholová ◽  
Karel Smrček
Keyword(s):  
Surface Area ◽  
Nickel Catalyst ◽  
Raney Nickel ◽  
Platinum Catalyst ◽  
Raney Nickel Catalyst ◽  
Electrochemical Parameters ◽  
Geometric Surface ◽  
Geometric Surface Area ◽  
Hydrogen Anode ◽  
In Cells

A hydrophobic porous hydrogen anode was prepared whose electrochemical parameters are comparable with anodes containing a platinum catalyst. For its successful preparation, oxidation of the Raney nickel catalyst with air oxygen or with fluorine from Teflon must be prevented. The electrodes of a geometric surface area up to 450 cm2 were tested in cells and modules filled with 7M-KOH.

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