Simultaneous quantitative analysis of N-acylethanolamides in clinical samples.

A simple and rapid analytical method is described for the simultaneous quantitative analysis of three different N-acylethanolamides in human biological samples: anandamide (AEA), oleoylethanolamide (OEA), and palmitoylethanolamide (PEA). The method is based on a new hybrid solid phase extraction-precipitation technology followed by ultra-performance liquid chromatography/mass spectrometry (UPLC/MS) analysis using d(4)-AEA as the internal standard. The method is linear up to 100ng/ml with a limit of quantitation of 50pg/ml for AEA and 100pg/ml for OEA and PEA. Good reproducibility, accuracy, and precision were demonstrated during the method validation. Application of this new methodology to the analysis of clinical study samples is presented.