A fast and direct liquid chromatography‐mass spectrometry method to detect and quantify polyunsaturated aldehydes and polar oxylipins in diatoms. (15th October 2016) - Kuhlisch, Constanze
Abstract: Polyunsaturated aldehydes (PUAs) are a group of microalgal metabolites that have attracted a lot of attention due to their biological activity. Determination of PUAs has become an important routine procedure in plankton and biofilm investigations, especially those that deal with chemically mediated interactions. Here we introduce a fast and direct derivatization free method that allows quantifying PUAs in the nanomolar range, sufficient to undertake the analysis from cultures and field samples. The sample preparation requires one simple filtration step and the initiation of PUA formation by cell disruption. After centrifugation the samples are ready for measurement without any further handling. Within one chromatographic run this method additionally allows us to monitor the formation of the polar oxylipins arising from the cleavage of precursor fatty acids. The robust method is based on analyte separation and detection using ultra high performance liquid chromatography‐atmospheric pressure chemical ionization mass spectrometry (UHPLC‐APCI MS) and enables high throughput investigations by employing an analysis time of only 5 min. Our protocol thus provides an alternative and extension to existing PUA determinations based on gas chromatography‐mass spectrometry (GC‐MS) with shorter run times and without any chemical derivatization. It also enables researchers with widely available LC‐MS analytical platforms to monitor PUAs. Additionally, non‐volatile oxylipins such as ω‐oxo‐acids and related compounds can be elucidated and monitored.