A strategy for validating concentrations of oxylipin standards for external calibration

Publication date: Available online 12 February 2019Source: Prostaglandins & Other Lipid MediatorsAuthor(s): Nicole M. Hartung, Malwina Mainka, Nadja Kampschulte, Annika I. Ostermann, Nils Helge SchebbAbstractQuantitative analysis of oxylipins by means of chromatography/mass spectrometry is based on (external) calibration with standard compounds. Therefore, the quality of analytical standards is of fundamental importance for accurate results. Recently launched certified standards with an assured concentration within a narrow range are useful tools for this purpose. However, such standards are only available for a few compounds.Based on the exemplary comparison of certified with none certified standards we suggest a tiered approach to validate and control the concentrations when preparing an external calibration based on non-certified oxylipin standards. Concentrations are evaluated by means of liquid chromatography negative electrospray ionization mass spectrometry (LC-ESI(-)-MS) in selected ion monitoring mode and UV spectroscopy (235 nm).Based on the suggested approach, more than 50% of the standards in our calibration mix could be validated. Though most of the non-certified standards are of good quality several oxylipin concentrations differ considerably demonstrating that a quality control strategy as suggested here is a mandatory prerequisite for quantitative oxylipin metabolomics.

Source: Prostaglandins and Other Lipid Mediators - February 13, 2019 Category: Lipidology Source Type: research