A MODIFICATION OF ARNOLD-GUNNING’S PROCEDURE FOR THE DETERMINATION OF NITROGEN IN THE BIOLOGICAL FLUIDS

　A modified Arnold-Gunning's procedure for the determination of nitrogen in biological fluids was presented. It enables the whole operation to be carried out on in the ordinary laboratory room without draught equipment. The digestion of the meaterials to be assayed is run in the test tubes inserted in a simple metal-wire digestion rack, and the digest is directly colorized with Nessler's reagent for photoelectric colorimentry, thus obviating the tedious process of distillation. The reliability of Hitachi's protein meter ( P.R.P-A type ) as an instrument to measure the serum protein concentration was assessed and approved by this method of nitrogen determination.