Nitrogen Determination in Pharmaceutical Active Peptides
Nitrogen and total protein determination in pharmaceutical products are described in the European Pharmacopoeia (Ph.Eur.) section2.5.9 and 2.5.33 method 7 [1, 2]. In the Pharmacopoeia of the United States (USP), nitrogen determination is described in section461 [3]. Therein, different titration techniques are specified.The Ph.Eur.describesback titration in the presence of the indicator methyl red mixed solution and the USP potentiometric boric acid titration.