Nitrogen constituent analysis

摘要

A unitary system is provided with separate channels for detecting and analyzing different types of nitrogen-containing compounds, particularly those which may be encountered in waste treatment or in pollution control or in food product analysis. The channels are so designed that an injected sample is acted upon in gaseous or suspended form, with reaction products thereof carried through the system by carried gas and ultimately converted to nitric oxide for analysis in a nitric oxide analyzer. Each channel contains reaction columns packed with a suitable substance. There is a total combined nitrogen channel in which a sample is first catalytically oxidized to form nitric oxides. In a nitrite-nitrate nitrogen channel a sample is first treated to form nitrites and injected into a reaction column packed with an acidifying substance and in an ammonia nitrogen channel the sample is injected into a reaction column packed with an alkalyzer before proceeding to a reaction column packed to catalytically oxidize the resulting ammonia to nitrogen dioxide and nitric oxide. In a modified embodiment a suitably pretreated sample suspected of cyanide content may also ultimately be converted to nitric oxide for analysis.