Abstract
1.
1. A study has been made of the contaminating effects of phospholipids in the titrimetric procedure of DOLE
1.
2.
2. Phosphatides were found to be extracted to varying degrees in the heptane phase of the method of Dole. None of the lysophosphatides was extracted.
3.
3. Unlike lecithin, phosphatidylethanolamine and phosphatidylserine were found to be titratable under the conditions used in the above method.
4.
4. Exclusion of cephalins by adsorption on silicic acid removed the interference and allowed for accurate free fatty acid estimation.
5.
5. The significance of these findings is discussed in relation to the extensive use of the Dole procedure without modification.