The use of organic solvents in laboratory freeze-dryer
Freeze-dryers were initially intended to be used with water as a solvent. With new applications, freeze-drying is consequently being used more and more in combination with organic solvents instead of water. Organic solvents and inorganic acids and bases are often used in research and development prior to lyophilisation of the sample. The behavior of these new types of samples during freeze-drying must therefore be considered prior to the process.
Nitrogen and Protein Determination in Animal Feed according to the Kjeldahl method
The determination of protein in feed is a routine procedure for quality assurance and labelling. A simple and fast method for protein determination in feed products according to the ISO 5983-2:2009 and AOAC 954.01 regulations is introduced below. The sample is digested with sulfuric acid and Kjeldahl Tablets Titanium using the digest Automat K-438, followed by distillation and titration with the KjelMaster K-375 with KjelSampler K-376.
Nitrogen Determination in Pharmaceutical Active Peptides
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 boric acid titration.