isobutyric acids are not separated from 

 each other. The method is capable of de- 

 termining 1 mg. of an individual acid in a 

 5-10 mg. mixture of the acids. 



Ramsey, L. L. andW. I. Patterson 



1948. Separation and determination of 

 the straight -chain saturated fatty acids 

 -^ C5 to C^o ^y partition chromatography. 



^ Journal of the Association of Official 



Agricultural Chemists, 31: 139-150. 

 C5 to Cio fatty acids are separated by 

 chromatography on silicic acid, using 

 methanol and 2,2,4-trimethylpentane as 

 solvent phases. Isomers of the same chain 

 length are eluted together. 



Ramsey, L. L. andW. I. Patterson 



1948. Separation of the saturated 



straight -chain fatty acids Cn to C^g. 

 ^ Journal of the Association of Official 



* Agricultural Chemists , 31 : 441-452. 



The fatty acids are separated by chroma- 

 tography on silicic acid, using furfuryl al- 

 cohol-2 aminopyridine and n-hexane as sol- 

 vent phases, and identified by titration with 

 NaOH. 



Rapport, M. M. and N. Alonzo 



1955. Photometric determination of fatty 

 _ acid ester groups in phospholipides. 



Journal of Biological Chemistry , 217: 

 193-198. 



Phospholipid esters are converted to hy- 

 droxamic acids, and the color produced 

 with acid ferric perchlorate is read" spectro- 

 photometrically at 530 m/i . The sensitivity 

 can be increased by decreasing the amount 

 of ferric perchlorate added. As little as 20 

 jj-g. of phospholipid can be measured by the 

 method. 



Carlson and Wadstrom (Scandinavian Jour - 

 nal of Clinical and Laboratory Investigation, 

 10: 407, 1958) found this methpd to be the 

 simplest, with good accuracy and ready re- 

 producibility. Hirsch (Journal of Biological 

 Chemistry , 233 : 213, 1958) recommends 

 substitution of n-butanol as solvent for cho- 

 lesterol esters, as it would circumvent the 

 insolubility of reaction products in the etha- 

 nollc ferric perchlorate color reagent. 



Rapport, M. M. and N. Alonzo 



1955. Identification of phosphatidal cho- 

 line as the major constituent of beef 

 ▲ heart lecithin. Journal of Biological 



Chemistry, 217: 199-204. 

 Modifications of the Schiff test and Korey 

 and Wittenberg's p-phenylhydrazone forma- 

 tion test ( Federation Proceedings, 13 : 244, 

 1954) are used for the identification of al- 

 dehydes. The methods are both quantitative, 

 and are in correspondence with each other 

 for phosphatidal choline analysis . 



Rapport, M . M . and B . Lerner 



1958. A simplified preparation of sphingo- 

 myelin . Journal of Biological Chemistry, 

 ^ 232: 63-65. 



A method is given for the preparation of 

 pure sphingomyelin from commercial beef 

 heart .lecithin by hydrolysis and solvent re- 

 crystallization . 



Reid, R . L . and M . Lederer " 



1951 . Separation and estimation of sat- 

 . urated C2-C7 fatty acids by paper par- 



tition chromatography. Biochemical 

 • Journal , 50: 60-67. 



The acids are separated by chromatog- 

 raphy of their amm^onium salts with a n- 

 butanol -aqueous ammonia solvent system. 

 The spots are located by spraying with a 

 bromocresol purple -formaldehyde solution 

 and the acids are estimated by measurement 

 of spot area. Accuracy + 2 to 5%. 



Rhodes, D. N. andC. H. Lea 



1955. Chromatographic separation of 

 glycerophospholipids . Proceedings of 

 J the International Conference on Biochem - 



. ical Problems of Lipids, 2nd Ghent 



(Pub. 1956) pp. 73-79. 

 The glycerophospholipids were separated 

 on silicic acid columns or silicic acid- 

 impregnated paper using chloroform -meth- 

 anol mixtures as eluting solvents. 



Rhodes, D. N. 



1958. Interference by polyunsaturated 

 fatty acids in the determination of cho- 

 lesterol. Biochemical Journal, 71 : 26P 

 Highly purified fatty acid esters were found 

 to give spurious colors in determination of 



57 



