Determination of Organic Nitrogen by Kjeldahl Method without

(2) Adler, I., and Axelrod, J. M., Spectrochim. Acta, in press. (3) Campbell, W. J., and Carl, H. F., .... SAMUEL NATELSON. Department of Biochemistry...
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V O L U M E 27, NO. 6, J U N E 1 9 5 5

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Table 111. Comparison of Determinations by X-Ray and Chemical blethods on Various Samples Sample

Thoria, % X-ray Chemical 0.7 9.5 F 4 6.50 4 7 4.4 0 2!? 0.19 0 71 0.78 1 02 0.96 2 1 2.2 2.3 2 0

chemical results. The average per cent difference for the 16 samples with more than 0.776 thoria is 4.770 and the maximum difference is 9.5%.

Difference.

%

hIonazite A 2 1 Alonazite B 6 2 11onazite C 6 8 hpatite 52 (j Magnetic separate 9 0 Carbonate 6 3 Heavy mineral eeparate 4.0 Siliceous rock 1 4 Xenotime 3 3 3 3 n Lignite ash Z,i Monazite from Mount Weathrr 5.8 3.3 Eschynite 0.0 6.4 3.1 Dilute monaziteY 0.97 1.00 3.0 Black sanda 3 li 3.6 0 Weathered vein materialn 1.80 1.68 7.1 Thorianite oren 1 80 1.87 3.7 1%-eatheredvein materiala 4.G 4.2 9.5 a Briquet contains 0.4-gram sample, 0.1 gram TIC1, 1.0 gram AI, 0.5 gram S i c . Counting for apatite is 5.3: for all others, 2.67a or less.

E.;

ACKNOWLEDGMEYT

The authors uish to thank the following members of the U. S. Geological Survey for furnishing both the samples and the chemical analyses: F. S. Grimaldi, Irving hlay, Harry Levine, and >I. I