tissues. Journal of Biological Chemis - 

 try, 123 . 623-636. 

 After alcohol -ether extraction of the lip- 

 ids, the ether -insoluble phosphatide is de- 

 termined by phosphorus analysis of the res- 

 idue which is insoluble in moist ether. Lec- 

 ithin is estimated by choline analysis of the 

 moist ether extract after Ba(0H)2 hydrolysis 

 by the method of Roman ( Biochemische Zeit - 

 schrift, 219: 218, 1930). Cephalin is cal- 

 culated as the difference in lecithin and to- 

 tal ether -soluble phosphatide. Cerebro- 

 sides are estimated by Kirk's modification 

 Qoumal of Biological Chemistry , 123: 613, 

 1938) of Kimmelsteil's method. The lee - 

 ithin precipitated with acetone -MgCl2 was 

 found to be wholly soluble in moist ether. 



Klee, Leo and G , H . Benham 



1950. The determination of the true io- 

 dine numbers of oils containing conju- 

 gated double bond systems. Journal of 

 # the American Oil Chemists Society, 27: 



130-133. Chemical Abstracts, 44: 

 51I9e (1950). 

 The modified Rosenmund-Kuhnhenn pro- 

 cedure is made suitable for determination 

 of iodine numbers of oils with conjugated 

 double bond systems by extending the reac- 

 tion time to 30-120 minutes. 



Klein, P. D. and E. T. Janssen 



1959. The fractionation of cholesterol 

 1^ esters by silicic acid chromatography. 



^ Journal of Biological Chemistry , 234: 



1417-1420. 

 A method is described for the separation 

 of cholesterol esters into groups consisting 

 of saturated, oleate, linoleate, and arachi- 

 donate esters by chromatography on a silicic 

 acid column. 



Klenk, E. andH. Langerbeins 



1941 . Distribution of neuraminic acid in 

 the brain. (With a micromethod for 

 the estimation of this substance in nerve 

 tissue.) Zeitschrift fiir physiologische 

 Chemie, 270: 185-193. Chemical Ab- 

 stracts , 37:899 (1943). 

 The neuraminic acid in about 30 mg. of 

 brain tissue can be detected by the orcinol 

 reaction. Tissue extract is heated with or- 



cinol reagent, centrifuged, and the red to 

 red-violet color obtained is read with a col- 

 orimeter. Galactose gives a green color 

 with the reagent, but will interfere only if 

 in large excess. 



Knight, H. B., L. P. Witnauer, J. E. Coleman, 

 W. E. Noble, Jr., andD. Swern 



1952. Dissociation temperatures of urea 

 complexes of long chain fatty acids, es- 

 9 ters, and alcohols. Analytical Chemis - 



try, 24: 1331-1334. 

 Methods for the preparation of urea ad- 

 ducts and determination of their dissocia- 

 tion temperatures are given. The dissocia- 

 tion temperatures of 42 compounds are giv- 

 en, and the use of the adducts as identifying 

 derivatives is discussed. 



Kobrle, V. and R. Zahrodnik 



1954. Paper partition chromatography of 

 . higher fatty acids. Chemicke Listy , 48 : 



* 1189-1196. Chemical Abstracts, 48: 



• 13546h (1954). 



Even -numbered Cj^q-C22 and C25 fatty 

 acids were separated by chromatography on 

 paper impregnated with a 12% toluene solu- 

 tion of vegetable oils. R^ values for various 

 solvent systems and papers are given. 



Koehler, A. E. andE. Hill 



1949. The molecular microdistillation of 

 cholesterol and cholesterol esters. 

 ■ Journal of Biological Chemistry, 179: 



1-10. 

 A small molecular still for use in analysis 

 of small amounts (up to 5 mg.) of lipids is 

 described. It was used for the quantitative 

 separation of cholesterol and cholesterol es- 

 ters by distillation. 



Koenig, R . A . and C . R . Johnson 



1942. Colorimetric determination of phos- 

 phorus in biological materials. Indus - 

 ▲ trial and Engineering Chemistry, Ana- 



lytical Edition, 14: 155-156. 

 Phosphorus is precipitated as phospho- 

 vanadiomolybdate and measured spectrophoto- 

 metrically. Effects of variables are discus- 

 sed. 



40 



