Quantitative extraction and determination of nonesterified fatty acids in plasma

A method is described for the determination of nonesterified fatty acids in plasma. Extraction is at least 98% efficient, and losses during subsequent stages are corrected for by the use of an internal radioactive standard. The method is suitable for reference purposes rather than for routine determinations. Higher values are obtained than by other methods of analysis, and it is suggested that some plasma fatty acids remain protein-bound after normal methods of extraction.