A simple method for the separation and quantification of neutral lipid species using GC‐MS

A simple gas chromatography‐mass spectrometry (GC‐MS) method has been developed for the determination of neutral lipids in yeast. This method was compared to the conventional thin‐layer chromatography (TLC) method used in our laboratory. The new method enabled the measurement of molecular species of diacylglycerols, triacylglycerols, and sterol esters (SE). With a classic lipid extraction, samples can be injected directly into the GC‐MS without any previous derivatization procedure. However, the main characteristic of this new method is its versatility because GC parameters can be modified based on the biological samples analyzed: volume and injection modes, derivatization of samples, etc. In order to validate the method, yeast lipid extracts from two distinct culture growth conditions were compared, the first in presence of oxygen and the second in its absence. Although the lipid profile of both yeast samples is qualitatively similar, the use of the GC‐MS method rather than the TLC method enables the identification of a sterol, neoergosterol, in yeast cells grown in absence of oxygen. Moreover, this method enables phospholipid detection in samples but their identification is difficult. GC‐MS total ion chromatogram of full chromatogram of yeast lipid extracts (positive values represent cells grown in the presence of oxygen while negative values represent cells grown without oxygen). STs: sterols; PLs: phospholipids; DAGs: diglycerides; SEs: sterol esters; TAGs: triglycerides.