Kjeldahl method


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Kjeldahl method

[′kel‚däl ‚meth·əd]
(analytical chemistry)
Quantitative analysis of organic compounds to determine nitrogen content by interaction with concentrated sulfuric acid; ammonia is distilled from the NH4SO4 formed.
References in periodicals archive ?
For the analysis of the total protein content, the most common procedure was the Kjeldahl method. Only one study analyzed all macronutrients (fat, protein and carbohydrate) and total energy in a single procedure, and for this analysis, the author used the spectrophotometric technique from the Human Milk Analyzer --Miris (Table 2).
Kjeldahl method (ASTM-D3179 standard) was adopted for the determination of Nitrogen in Coal samples.
Total protein were calculated by Kjeldahl method, 6.025 factor were used for the conversion of protein, ash were determined by direct analysis in muffle furnace for 12 h at 550AdegC, moisture content were calculated by the oven drying method for 6-7 h at 110AdegC temperature and total lipid was extracted by Soxhlet method.
Now we know that this is called the determination of the mass fraction of protein by the Kjeldahl method. Sports nutrition is popular among young people.
Concentrations of sarcoplasmic protein and myofibrillar protein were measured by Lowry method, and the myostromin concentration was assayed by Kjeldahl method. Each experiment was performed 3 times and the means were reported.
The total nitrogen amount was measured using the Kjeldahl method as described in SFS 5505 [17].
Kjeldahl method was used for estimation of protein content and carbohydrate content was determined by the differential method.
At the end of each collection period, the weight and total volume of urine were measured, and the total N content was determined using the Kjeldahl method INCTCA N-004/1 [14].
This mix was incubated for two weeks and its ammonia content was analysed by Kjeldahl method. The Kjeldahl method may be broken down into three main steps: digestion, distillation, and titration as reported by Bremner and Tabatabai [13].
Protein was determined using the semi-micro Kjeldahl method. One gram of ground sample from each of the two samples (smoked and sun dried) was digested in a Kjeldahl flask using 98% Sulphuric acid and a catalyst made from Potassium sulphate and Cupric sulphate.
Total nitrogen content of the NAM pellet was analyzed by the Kjeldahl method as described in AOAC (2002) and multiplied by a factor of 6.25 to quantify the protein content.
Extractions were performed in triplicate, and the protein content of the extracts was measured by the Kjeldahl method [16].