New reagent for use in determination of blood urea nitrogen, with special reference to manual analysis.

I N THE METHOD for the determination of blood urea imitrogeit described by us in Clinical Chemistry, 5, 617 (1959) a suli uric arsenic pentoxide solution is used for the reaction between diacetvl nionoxime and urea. Since the article was published tile manufacturer of time systeln* has recommended tile use of a ferric-alum-acid reagent developed by P. Paubiollsky and based on proposals by F. McGiickin for automatic analysis. We are using this new reagent ill automatic analysis and also with good results hi the manual metlmod, which is thereby simplified 1)ecause turbidity in the test solution is eliminated. Fomthe benefit of those laboratories in which automatic analysis is not used, we preseilt below these changes in the method witim reference to our iaper mentioned above.