Application Note: Nitrogen/Protein In Feeds, Grains, And Oil Seeds Using The TruMac

Protein determination is one of the most significant nutrient components. The accurate and precise determination of protein not only plays a role in the characterization of nutritional or dietary value in feed materials but is also key to the economic value of these materials. Protein in feed products is most commonly calculated using the measured nitrogen in the sample and a multiplier (protein factors vary according to the sample matrix). Nitrogen determination is performed using either the classical wet chemical method (Kjeldahl) or a combustion method. The Kjeldahl method is capable of handling macro samples sizes >1 g typically utilized for heterogeneous feed product samples. Physical restrictions in sample encapsulation and realities of handling the ash build up within a vertical furnace combustion nitrogen instrument will often restrict the sample mass to ~300 mg or less making the accurate analysis of heterogeneous feed products difficult. The LECO TruMac N combustion nitrogen determinator has been designed to handle macro sample sizes (~1g) while maintaining a rapid analysis time of 4.8 minutes with a low cost-per-analysis.