In metabolomics studies, large sample sets have to be analyzed to allow statistical differentiation of sample types. Obviously, repeatability of the whole analytical workflow, including sample preparation, sample introduction, separation and detection, is hereby of the utmost importance. In this respect, automation of the sample preparation is very useful in order to reduce the analytical variability.

In a series of articles, we describe the use of the Gerstel MPS WorkStation for automated sample preparation applied to metabolomics studies. In a first part, an automated ultrasonic assisted extraction and filtration method was discussed. In this second part, an automated fractionation of lipid classes using solid phase extraction (SPE) is presented. The SPE fractions are concentrated using an mVAP evaporation station and re-dissolved in small amounts of solvent, followed by LC-QTOF analysis.