Single derivatization method for routine analysis of bacterial whole-cell fatty acid methyl esters, including hydroxy acids

Analysis of fatty acid methyl esters prepared from whole-cell bacteria by sodium hydroxide hydrolysis and boron trichloride-catalyzed methylation showed degradation of hydroxy acid peaks after several injections on a fused silica capillary column. A simple base wash of the extracts before injection prevented the tailing of the hydroxy acid peaks even after extended use. This eliminates the need to form trifluoroacetic anhydride derivatives of the hydroxy acids.