Fundamental studies in automatic nitrogen digestion

Abstract

Little work has been reported on the inter-relationship between digestion temperature, media and catalysts in the AutoAnalyzer digestor system.

Although classical results could be used to some extent, many phenomena observed could not be explained by means of current theory. The volume of acid in the digestor helix has been found to be critical, and failure to realise this has resulted in loss of nitrogen. Hypotheses are advanced to explain where this nitrogen loss takes place, and subsidiary investigations of catalyst and digestion-media systems were undertaken. The final digestor system is shown to give 99·5 per cent. recovery for ring compounds such as nicotinamide, when compared with ammonium sulphate standards taken through the same system. Theories are also elucidated that point to the reasons for the short digestion times, normally minutes, in which digestion is completed.