Nitrogen determination in dihtheria and tetanus toxoids
KjelMaster System K-375 / K-376, KjelDigester K-449, Scrubber K-415
Nitrogen and total protein determination in pharmaceutical products are described in the European Pharmacopoeia (Ph.Eur.) section 2.5.9 and 2.5.33 method 7 [1, 2]. In the Pharmacopoeia of the United States (USP), nitrogen determination is described in section 461 [3]. Therein, different titration techniques are specified. The Ph.Eur. describes back titration in the presence of the indicator methyl red mixed solution and the USP potentiometric and colorimetric boric acid titration.