การเกษตรและเทคโนโลยีชีวภาพ
เอกสารมาตรฐาน
สหรัฐอเมริกา
AOAC
2001.11
Protein (Crude) in Animal Feed, Forage (Plant Tissue), Grain, and Oilseeds: Block Digestion Method Using Copper Catalyst and Steam Distillation into Boric Acid
2005 (2023)
Final Action
9
AOAC 2023 Online Ch. 4.2.11
The material is digested in H2SO4 to convert the protein N to (NH4)2SO4 at a boiling point elevated by the addition of K2SO4 with a Cu catalyst to enhance the reaction rate. Ammonia is liberated by alkaline steam distillation and quantified titrimetrically with standardized acid. Aluminum block heaters increase the efficiency of the digestion ...