Dumas Microdetermination of Nitrogen in Refactory Organic Compounds. Modification of Zimmermann's Method

Sternglanz, P. D.; Thompson, Ruth; Savell, Walter L.

doi:10.1021/ac60055a029

Cited by 15 publications

(4 citation statements)

References 22 publications

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“…While searching for a modification which would improve the analysis of refractory compounds, several oxidation aids recommended by other workers (1,9,13,14,(16)(17)(18) were tried. Some oxidation aids did not improve the results at all.…”

Section: Discussionmentioning

confidence: 99%

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Evaluation of an Automatic Nitrogen Analyzer for Tractable and Refractory Compounds.

Sternglanz¹,

Kollig²

1962

Anal. Chem.

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If the acidity of the solution is too high, the amine is also protonated to a great extent and cannot add to the protonated aldehyde. If the acid concentration is too low, not enough of the aldehyde is protonated to cause a significant rate of addition of the amine.Samples of n-butylamine mixed with equimolar quantities of di-n-butylamine, tri-n-butylamine, and ammonia were titrated according to this procedure, and no interference due to the presence of these added bases was noticed. The results of the titration of the above mixtures were all within two standard deviations of the mean of the results of n-butylamine alone.Repeated attempts were made to titrate primary aliphatic amines in the presence of primary aromatic amines without success. Although the aromatic amines do not react appreciably with %ethylhexanal under the reaction conditions employed for the titration, the intrinsic ultraviolet absorbance of the aromatic amines a t 305 mp causes the absorbance of the solution being titrated to be so great that the relative change in absorbance during titration is very small. A number of aromatic aldehydes were tried as titrants, but none of these reacted rapidly enough with the aliphatic amines to make a practical titration possible.Crotonaldehyde, Lvhose carbonyl absorption peak is a t 325 mp instead of 295 mM, was also tried as a titrant, but unfortunately crotonaldehyde reacts to a significant extent with many aromatic amines while reacting only slowly with most aliphatic amines. Thus, the procedure reported can tolerate the presence of only a small amount of an aromatic amine or any other substance whose intrinsic absorbance at 305 mp is high.

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Section: Discussionmentioning

confidence: 99%

“…Cobaltous-cobaltic oxide (9,14,18) was without effect and attacked the combustion tube a t 900" C. Manganese dioxide (IS) was without effect. Mixing the sample with copper oxide powder in a vibrator gave no improvement Addition of potassium dichromate (5) raised low results insufficiently and lacked reliability.…”

Section: Discussionmentioning

confidence: 99%

Evaluation of an Automatic Nitrogen Analyzer for Tractable and Refractory Compounds.

Sternglanz¹,

Kollig²

1962

Anal. Chem.

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“…Provided the compound studied does not set up secondary reactions with nitric acid, the proposed method provides a means of determining amine nitrogen of -amino acids and -amino sulfonic acids and the amide nitrogen of amides and sulfonamides. Stemglanz et al (132) reported a modification and simplification of Zimmermann's Dumas method for nitrogen. Tractable samples were mixed with fine copper oxide in a porcelain boat before being placed in the combustion tube, whereas copper oxide plus cobaltic oxide was used if the material was refractory.…”

Section: Elemental Analysismentioning

confidence: 99%

Organic Microchemistry

Willits¹,

Ogg²

1952

Anal. Chem.

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“…Pyrolysis of the sample is carried out byr a traveling electric furnace (3,10) in a stream of carbon dioxide, and any' carbonaceous residue is then completely burned in a stream of oxygen as described by' Gonick et al (2). This technique eliminates the necessity for mixing the sample with copper oxide or other oxidation aids when testing refractory compounds (11). Errors inherent in the measurement of the nitrogen volume in an azotometer filled with strong potassium hydroxide solution (13) are eliminated by use of the mercury-filled weight azotometer described by Koch et al (7).…”

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confidence: 99%