简介:The potentiometric titration of Kjeldahl nitrogen is one of the most widely employed
analytical methods. Many of the standard procedures used in the food and animal
feed industry, in waste water and refuse analysis as 简介:The potentiometric titration of Kjeldahl nitrogen is one of the most widely employed
analytical methods. Many of the standard procedures used in the food and animal
feed industry, in waste water and refuse analysis as well as in agriculture and the
fertilizer industry are based on this method. Extensive test series (interlaboratory
tests) have been carried out to determine and optimize the recovery rates and digestion
conditions. The knowledge derived from these tests has been integrated in
the corresponding standards.
Normally, the samples are digested with concentrated sulfuric acid using a catalyst
as admixture. The ammonium sulfate formed is distilled off as ammonia in alkaline
solution, collected in an absorption solution and then titrated.
The first part of this bulletin describes in detail the potentiometric determination of
nitrogen after distillation of the digestion solution. The second part indicates the
possibilities of the coulometric titration (without distillation).详细>