通常在分析有机肥料中的氮时,应用得最多的是比较陈旧的克氏定氮法。该法将试样在多量的浓硫酸作用下,使有机氮化合物转变成无机的铵盐,然后用蒸馏法测定铵。为了避免蒸馏法测铵的繁琐费时,有些研究工作者提出了一些不用蒸馏的其他测定法。其中最简便的是将消解液中和,加入定过量碱,使铵分解,然后用酸回滴剩作的碱。但此法不甚严密,影响测定的因素较多。若操作不当,所得结果的误差也较大。目前非蒸馏法中应用得最多的是甲醛法测铵,由于重金属离子有干扰,消解时不能加入催化剂以加速消解 Often the most commonly used method of determining nitrogen in organic fertilizers is the older Kjeldahl method. The method will be the sample in the presence of large amounts of concentrated sulfuric acid, the organic nitrogen compounds into inorganic ammonium salt, and then measured by distillation ammonium. In order to avoid the cumbersome and time-consuming determination of ammonium by distillation, some researchers have proposed other assays that do not use distillation. One of the most convenient is to neutralize the digestion solution, adding excess alkali, the ammonium decomposition, and then use the acid back to the left for the base. However, this method is not very strict, affecting the determination of many factors. If improper operation, the resulting error is larger. At present, the most commonly used non-distillation method is the formaldehyde method to measure ammonium, due to the interference of heavy metal ions, digestion can not be added to accelerate the digestion of the catalyst