Determination of volatile N and urea N in fish by means of microdiffusion and distillation in vacuo.

摘要

Being quantitatively equal the two independent analytical manners of proceeding, viz. distillation in vacuo and microdiffusion after the Conwayprinciple, are recommended for the estimation of different forms of volatile N and urea N. The two methods fill each other out, the distillation in vacuo being a typical rapid method while estimations performed in Conway units are well fit for mass analyses. Sera made at pH= 5,2 either by means of hydrochloric acid or by colloidal iron were used during these investigations. Analytical data showing the content of total volatile N, trimethylamine N and urea N in fresh and stored fish, also in the salted, smoked and frozen state, are given.