macro-Kjeldahl method

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mac·ro-Kjel·dahl meth·od

(kyel'dahl),
a procedure for analyzing the content of nitrogenous compounds in urine, serum, or other specimens, usually to determine relatively large amounts of nitrogen (for example, 20-100 mg); the specimen is treated with a digestion mixture (copper sulfate and sulfuric acid), heated thoroughly, and made alkaline with a solution of sodium hydroxide; ammonia is then distilled from the mixture, trapped in a boric acid-indicator solution, and titrated with standard hydrochloric or sulfuric acid.
[Johan G. C. Kjeldahl]

Kjeldahl,

Johan G.C., Danish chemist, 1849-1900.
Kjeldahl apparatus - an apparatus used in nitrogen analysis.
Kjeldahl method
macro-Kjeldahl method - a procedure for analyzing the content of nitrogenous compounds in urine, serum, or other specimens.
micro-Kjeldahl method - a modification of the macro-Kjeldahl method designed for the analysis of nitrogenous compounds in relatively small quantities.
References in periodicals archive ?
(8) Type 1 DM (1) The total protein was determined by the Kjeldahl method, lactose by enzymatic hydrolysis and fat by gravimetry after extraction with methylene chloride by the modified Roese-Gottlieb method Bitman et al.
The ammonia nitrogen (N-NH3) concentration was determined after samples were centrifuged at 3,000 rpm/15 min, using the supernatant for analysis by Kjeldahl method INCT-CA N-007/1 [14].
The first test was ammonia determination by Kjeldahl method; six bacterial cultures were kept in soil for two weeks to find the microorganism, which could highly produce ammonia.
The a-amino nitrogen was determined by formol titration according to the method as described by Taylor [10], and the total protein nitrogen was determined by the Kjeldahl method [11].
roseapbrunner for WSPP and WSPC, respectively, in comparison with that of its protein content, which was determined by the Kjeldahl method [16].
Nitrogen, Sulfur, pectin, lignin, cellulose and hemicellulose were determined for acid digestion according to Kjeldahl method, which consists in the destruction of the sample with concentrated sulfuric acid in boiling, thus separating the nitrogen from its bond matrix and transforming into ammoniacal nitrogen, with a heating period of 4.5 h at 400[grados]C (15).
Protein determination: Protein in the sample was determined by Kjeldahl method (Barbano and Clark, 1990).
The protein content of the samples was analyzed using the analytical Kjeldahl method. A protein-peptide profile analysis was conducted using sodium-dodecyl-sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and imaging analysis software.
The percentage of carbon was determined by dichromatometry and [N.sub.total] by the Kjeldahl method. Sodium was determined by dilute hydrochloric acid solution and was subsequently determined using flame spectrophotometric apparatus.
The protein content in the supernatant was determined by the Kjeldahl method and percent protein solubility was calculated as follows:
The N contents of grains were obtained by the kjeldahl method [15] and multiplied by 6.25 based on dry weight to calculate grain protein content (%).
Nitrogen content of dried camel milk was determined by Kjeldahl method and then multiplying that by a factor 6.37.