标准摘要
[中文适用范围]： 该方法包括：在酸性介质中使用铬粉将硝酸盐还原为氨；在催化剂存在下，用浓硫酸消化使有机氮和尿素氮转化为硫酸铵；将氨从碱性溶液中蒸馏出来，并使其被过量的标准体积氢氧化钠溶液吸收。该方法不适用于有机物质含量超过7%的材料。 [外文原描述]： The method consists in reducing of nitrate to ammonia by chromium powder in acid medium, converting of organic and urea nitrogen into ammonium sulfate by digestion with concentrated sulfuric acid in the presence of a catalyst, distilling of the ammonia from an alkaline solution and absorbing in an excess of standard volumetric sodium hydroxide solution. The method is not recommended for materials containing more than 7 % of organic matter.
英文名称Fertilizers — Determination of total nitrogen content — Titrimetric method after distillation