Nitrogen analysis of whole seeds

Whole seeds were digested in sulfuric acid with catalyst in conical beakers on a hot plate and the digest was analyzed for nitrogen. The nitrogen analysis of the digest can be performed by distillation-titration or colorimetrically, using manual or automatic procedures, linear regression analyses of 8 samples of 16 soybeans each gave values that agreed within 2% of those obtained by the standard Kjeldahl procedure. Precision of the method is 1.8 relative standard deviation compared with 1.4 relative standard deviation for the standard method. The whole seed procedure gives results that are independent of seed size and has been applied to samples of both oilseeds and cereal grains.