ANALYTICAL EDITION
September 15, 1943
595
that on the average the discrepancy between the two methods does not exceed 15 per cent for integrated runs.
the Rayon Department for fostering this research and permission to publish these results.
Acknowledgment
Literature Cited (1) Dobson, G. M. B., Proc. Phys. SOC.,43,324-39 (1931). ( 2 ) Hanson, v. F.,IND.ENG.CHEM., -4NAL. ED.,13,119 (1941). (3) Moorhead, F. F., Ibid., 12, 373 (1940).
The author wishes to express his appreciation to V. F. Hanson of the Electrochemicals Department, du Pont Co., for many suggestions, to J. W.Ballou and W. H. Warhus, Pioneering Research Section, Technical Division, Rayon Department. for much valuable help, and to other members of
(4) White, B. E., and Calvert, W. R., J . Ind. Hug. Tozicol., 23, 196 (1941). (5) White, B. E., Reece, G . &I., and Drinker, P. J., Ibid., 22, 416 (1940).
Yolk Nomograph for Mayonnaise and Salad Dressing D. S. DAVIS Wyandotte Chemicals Corporation, Wyandotte, Rlich.
I
N CONNECTION with the determination of commercia1 egg yolk in mayonnaise and s a l a d d r e s s i n g , Cahn and Epstein (2) presented the equation Y = 2899P g
q, Per
cent
golids
9
4% 017a
Per cent
n! nitrogen
Key:
094
P-I-N
0.05
LY-Y-q
- 69N
- 12.2
where
Y = per cent of commercial yolk P = per cent phosphorus pent-
h'
oxide
=
per cent nitrogen
0.10
g = per cent solids content of yolk
This equation, consistent with those of the Association of OfficialAgricultural Chemists ( 1 ) and based on the analytical data of Mitchell (S), can be solved conveniently and accurately by means of the accompanying nomograph. The use oi the chart is illustrated as follm s: What is the percentage of commercial egg yolk, containing 43 per cent solids, in mayonnaise which tests 0.08 per cent phosphorus pentoxide and 0.11 per cent nitrogen? Following the key, connect 0.08 on the P scale with 0.11 on the iV scale and note. the intersection with the CY axis. Connect this point with 43 on the g scale and read the percentage of egg yolk o n the Y scale as 7.3.
Literature Cited Official Agr. Chem., Official a n d T e n t a t i v e Methods of Analysis, 5th ed., p. 476, paragraph 53 (1940). ( 2 ) Cahn, F. J., and Epstein, A. K., IND. ENG.CHEW,ANAL.ED., 15, 281 (1943). (3)-Mitchell, L. C., J . Assoc. O.#icial Agr. Chem., 15, 317 321 (1932).
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/ 0.20
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0.25
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40
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(1) Assoc.
45
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