Automated determination of protein-nitrogen in cereals and grains.

This paper presents the design, performance, and operational characteristics of a new direct reading instrument for determining nitrogen in cereal and grain. Precision, accuracy, range, speed, ease of operation, sensitivity, sample size, and flexibility of the instrument are presented. Results on various cereals and grains are presented and compared with those obtained by the Kjeldahl technique. The apparatus is the result of research for a rapid method for determining nitrogen in organic material. The instrument uses a combination of a unique high temperature sample oxidation, a sampling valve for separating combustion products, and thermal conductivity detection for the liberated nitrogen in a helium carrier gas.