Van Slyke Manometric Apparatus Modified for Determination of Free Amino Nitrogen in Solid Samples

1956 ◽  
Vol 28 (1) ◽  
pp. 144-144 ◽  
Author(s):  
K. T. Williams ◽  
M. C. Long
1948 ◽  
Vol 15 (3) ◽  
pp. 364-368 ◽  
Author(s):  
C. H. Lea

The reaction of casein and of fresh and deteriorated milk protein with nitrous acid has been followed at constant temperature for 4 hr. in the manometric apparatus of Van Slyke, and simplified procedures suggested whereby the method can be utilized for investigation of the deterioration of the protein of separated milk powder during storage.Technical assistance in this work was given by Mr L. J. Parr: The work was carried out as part of the programme of the Food Investigation Board of the Department of Scientific and Industrial Research.


1977 ◽  
Vol 60 (4) ◽  
pp. 805-806
Author(s):  
Dwight B West

Abstract The American Society of Brewing Chemists (ASBC) has released new methods for the determination of free amino nitrogen in wort and beer and for viscosity of wort and beer. The 4 procedures have been collaboratively tested by ASBC and the European Brewing Convention and adopted as official by both organizations. The free amino nitrogen methods use ninhydrin in the colorimetric reaction. The viscosity procedures measure flow times of the test materials against water. The methods have been adopted as official first action.


1954 ◽  
Vol 99 (6) ◽  
pp. 637-646 ◽  
Author(s):  
N. Kretchmer ◽  
Francis J. Cherot

Parenteral injection of amino acids resulted in the formation of Gram-positive droplets in the cytoplasm of the proximal convoluted tubule cells of the kidney of the rat within 15 minutes after intravenous administration. At this time the free alpha amino nitrogen in the cortex of the kidney had increased 2-fold. At the end of 1 hour this level was still somewhat higher than that of the control animals. The administration of increasing amounts of the amino acid disclosed the existence of a maximal concentration level in the renal cortex. When it was reached droplets appeared. Fractionation of the cells 15 minutes after the injection of lysine resulted in the recovery of free amino acid in the supernatant fluid but 1 hour after the injection lysine was contained within the particulate protein of the fractions which contain droplets. The increase in lysine was of the order of 2- 3-fold. It is concluded that the mitochondria-droplet complex is a locus of amino acid concentration and metabolism within the cytoplasm of the renal cell. A method is described for the determination of lysine in micro quantities.


1950 ◽  
Vol 182 (1) ◽  
pp. 29-37
Author(s):  
P.E. Schurr ◽  
H.T. Thompson ◽  
L.M. Henderson ◽  
C.A. Elvehjem

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