6] Separation of partialy deuterated methyl palmitate from nondeuterated methyl palmitate by high-pressure liquid chromatography

Abstract

This chapter describes separation of partially deuterated methyl palmitate from nondeuterated methyl palmitate by high-pressure liquid chromatography. High-pressure liquid chromatography columns of high efficiency have made possible separations of fatty acids that could be accomplished only by gas chromatography. Methyl esters of fatty acids were isolated from 1.75 g of rat liver that had been perfused with 70% D20. Gas chromatographic analysis of the total lipid extract showed that the methyl palmitate contained 13.7% deuterated palmitate. Methyl esters of the saturated fatty acids were then separated from methyl esters of all unsaturated fatty acids on a silver nitrate-impregnated silica gel column, 0.41 cm in diameter and 25 cm in length, packed with Adsorbosil-5-ADN 25% AgNO 3 . It is found that for separation of the deuterated and nondeuterated palmitates, the material was injected into the same column and elution with methanol was started. It is observed that after elution of one column volume, the recycle valve was closed and the methyl palmitate was allowed to recycle 13 times.