A simple liquid chromatography method running in dual modes for quantification of short and medium chain fatty acids

Sample preparation is often a rate-limiting step in quantification of short chain and medium chain fatty acids (SFAs and MFAs) in biological samples. A novel liquid chromatography (LC) method with simple sample preparation is introduced in this report. The method is performed on a column packed with polyvinyl alcohol sorbents. In separation of a mixture of bovine serum albumin (BSA) with SFAs and MFAs, the protein is eluted in size-exclusion mode in the first part of the chromatogram. SFAs and MFAs are then eluted in the second part of the chromatogram in reverse-phase mode where fatty acids with longer carbon lengths are eluted at longer retention times. SFAs and MFAs are well resolved from each other without pre-column derivatization. The size-exclusion mode affords good tolerance to macromolecules in sample matrixes. The dual mode separation allows sample injections without complicated sample preparation steps, such as derivatization, extraction, evaporation, and reconstitution.