Abstract
The effect of temperature on the rate of
Kjeldahl digestions in the absence of catalyst and oxidizing agent has been
studied. Both the clearing time and the minimum time for complete recovery of
nitrogen are markedly decreased by raising the digestion temperature. The
appreciable rise in temperature during prolonged digestions and the effect of
time and temperature on the pyrolytic loss of nitrogen are considered. By
proper choice of digestion conditions nitrogen can be completely recovered in a
reasonable time even from refractory compounds. The time may be further
decreased by the use of mercury as catalyst.
The use of hydrogen peroxide as an oxidant
in Kjeldahl digestions is discussed and the effects of the volume and number of
additions at various temperatures after different cooling times determined.
Earlier claims regarding complete recoveries with few additions cannot be
substantiated.
A modified micro-apparatus for the
distillation of ammonia from Kjeldahl digestions is described and acidimetric
methods for the determination of the ammonia are critically examined.
As a result of this work it is possible to
develop procedures for the Kjeldahl determination of nitrogen in various
materials. A rapid and precise method for the determination of 0.2-2 mg of
nitrogen in amino acids and proteins is described.
Cited by
763 articles.
订阅此论文施引文献
订阅此论文施引文献，注册后可以免费订阅5篇论文的施引文献，订阅后可以查看论文全部施引文献