The evaluation of the Kjeldahl digestion method was investigated by comparing measured values of total nitrogen, phosphorus and potassium using three salt and catalyst mixture in Standard Kjeldahl digestion method and Salicylic acid Modification method with certified values of plant material as well as comparison was made for determination of total nitrogen from steam distillation method verses...

Measurement of total nitrogen by Kjeldahl analysis is the historical reference method for determination of the protein content of dairy products and is used for both calibration and validation of alternative methods for protein determination. Accurate evaluation of alternative methods is not possible if there is large uncertainty regarding the reference values. When Kjeldahl analysis is used to...

A coulometric method is described for the determination of ammonia resulting from micro-Kjeldahl digestion of protein samples. The method has been applied to the direct titration of the ammonia in the digests. Routine titration of the ammonia resulting from lOsl. serum samples is described; the method has been applied to 1 -JLI. samples. Results are compared with standard macroand micro-Kjeldah...

Jean Dumas (Fig. 1) published his combustion method in Paris back in 1848. This makes the method considerably older than Kjeldahl digestion. While researching the composition of natural oils, Dumas tried combusting his samples, initially to analyse the carbon and hydrogen contained therein. Combustion therefore makes it possible to analyse multiple parameters, while Kjeldahl digestion is only s...

The micro-Kjeldahl method for nitrogen determination has been widely used in organic chemistry laboratories in recent years. The value of this method, developed through the brilliant researches of PiLcH, BANG, PARNAS and WAGNER, PREGL, and coworkers, has justified its application to industrial and clinical problems. Plant physiologists have not generally adopted quantitative micro-methods for n...

A method for the determination of nitrogen in ruminant feedstuffs, products and excreta (e.g. milk and urine) using a spectrophotometer is developed, where samples processed for P determination are also used to determine N. Samples are digested with sulphuric acid and subsequently with hydrogen peroxide in Kjeldahl tubes. Digested solutions along with phenol and buffered alkaline hypochlorite r...