of oils, fats and waxes . Industrial and 

 Engineering Chemistry, Analytical Ed- 

 ition , 4: 257-259. 

 A method is described in which the hy- 

 droxyl number is determined by reaction 

 of the sample with acetic anhydride in a 

 sealed tube, after which the excess anhy- 

 dride is hydrolyzed and titrated. 



Robins, E., O. H. Lowry, K. M. Eydt, and 

 R. E. McCaman 



1956. Microdetermination of phospho- 

 lipides and sphingolipides in brain. 

 A Journal of Biological Chemistry , 220: 



661-675. 

 Cephalins, lecithins, and sphingolipids 

 were determined in 10 jJLg. of brain tissue 

 by a modification of the method of Schmidt, 

 et^ (Journal of Biological Chemistry, 166: 

 505, 1946). 



Roboz, E., W. C. Hess, R. R. DiNella, and 

 W. Cevallos 



1958. Determination of total lipids, cho- 

 # lesterol, and phospholipids in cerebro- 



A spinal fluid. Journal of Laboratory and 



■ Clinical Medicine, 52: 158-162. 



Methods suitable for use in the determina- 

 tion of total lipids, free and esterified cho- 

 lesterol, and phospholipids in spinal fluid 

 are described. 



Roman, W. Ill 



1930. A chemical method for the deter- 

 mination of choline and some physico- 

 chemical data on choline and its salts . 

 A Biochemische Zeitschrift, 219: 218- 



231. Chemical Abstracts, 24:3029 

 (1930). 

 Choline is precipitated as choline per- 

 iodide with I2, and the excess I2 is titrated 

 with Na2S203. Determines 5^g. to 5 mg. 

 of choline with accuracy of + 5%. 



Rose, A. R., F. Schattner, andW. C. Exton 

 1941. A method for determining blood 

 cholesterol. American Journal of Clin- 

 ical Pathology, Supplement 5: 19-23. 

 Cholesterol is extracted with alcohol - 

 acetone (1:1) and determined colorimetri- 

 cally with the ZnCU -acetyl chloride reac- 

 tion (Tschugaeff, Chemiker -Zeitung, 24: 



542, 1900). 



Rosen, H. 



1957. A modified ninhydrin colorimetric 

 analysis for amino acids.. Archives of 

 Biochemistry and Biophysics, 67: 10- 

 15. ~ 



A modification of the method of Yemm 

 and Cocking ( Analyst, 80: 209, 1955) which 

 avoids the use of unstable solutions of re- 

 duced ninhydrin. 



Rosenmund, K . W . and W . Kuhnhenn 



1923. A new method for the determination 

 of the iodine number in fats and oils by 

 the use of pyridine sulfate dibromide. 

 Zeitschrift fur Untersuchung der Nahr- 

 ungs- und Genussmittel , 46 : 154-159. 

 Chemical Abstracts, 18:477(1924). 

 The sample is brominated by using pyri- 

 dine sulfate dibromide reagent, and the ex- 

 cess reagent is titrated iodometrically . 



Rosenthal, H . L . , M . L . Pfluke, and 

 S, Buscaglia 



1957. A stable iron reagent for the de- 

 termination of cholesterol. Journal of 

 ■ Laboratory and Clinical Medicine, 50: 



318-322. ~~ 



The use of phosphoric acid in place of 

 glacial acetic acid as solvent for ferric 

 chloride gave a more stable reagent for cho- 

 lesterol determination. The reagent may 

 be stored at room temperature instead of 

 frozen, as is required by the acetic acid so- 

 lution . The results found by using the new 

 reagent agreed well with other methods, 



Rosenthal, H. L., M. L. Pfluke, and 

 J. Callerami 



1959. The colorimetric estimation of se- 

 _ rum fatty esters . Clinica Chimica Acta, 



• ±: 329-333. 



A modification of the Stern and Shapiro 

 (Journal of Clinical Pathology, . 6: 158, 1953) 

 hydroxamic acid procedure which uses cho- 

 lesterol acetate as a standard in place of 

 olive oil. 



Rossi, L., A. D. Marenzi, and R. Lobo 



1942. Photometric microdetermination of 

 the chromate ion. Anales de farmacia 



59 



