Apparatus for determining small amounts of nitrogen

摘要

The nitrogen content of a substance is determined by digesting the substance in a sealed container at superatmospheric pressure in a liquid acid medium until the nitrogen is converted to ammonium ions, the medium is alkalinized, and the ammonia liberated thereby is driven from the alkalinized medium into an acidic aqueous medium by steam distillation in a closed system in which the steam used is generated from the acidic aqueous medium. The latter then is adjusted to a weakly alkaline pH, and the ammonia present is oxidized to nitrogen by hypobromite ions electrolytically generated from bromide ions in the adjusted solution. The amount of current consumed is determined as a measure of the nitrogen originally present.