HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Lin, R. H. Articles by Randolph, H. E. Search for Related Content PubMed Articles by Lin, R. H. Articles by Randolph, H. E.

Determination of Nitrogen in Milk by Microdiffusion of Kjeldahl Digests¹

Department of Animal Science, Texas A&M University, College Station 77843

ABSTRACT

Recovery of ammonia from ammonium sulfate solutions. (.01 M to .0005 M) by a modified Conway microdiffusion procedure did not differ significantly from recovery by micro-Kjeldahl distillation. Total and whey-protein nitrogen concentrations of milk were determined by microdiffusion and microdistillation of Kjeldahl digests. Protein values by microdiffusion and microdistillation for 38 samples of milk from individual cows (3.38 and 3.42%) and 40 samples of acid-prepared whey (.87 and .88%) did not differ significantly although results by microdiffusion were consistently lower (1 to 3%) than microdistillation values. The correlation coefficient for the two methods was .99. Recovery of nitrogen by the microdiffusion procedure is influenced by the digestion catalyst. The microdiffussion procedure provides a means of reducing work time while maintaining the quantitative accuracy of the micro-Kjeldahl distillation.

¹ Technical article 13198 of the Texas Agricultural Experiment Station, College Station.

² H. P. Hood, Inc., Boston, MA 02129.

³ H. E. Randolph, Consulting Services, Bryan, TX 77801.