Nodularins belong to the class of hepatotoxic cyclic pentapeptides and have their structures resembling to that of microcystins. They are produced by Nodularia spumigena cyanobacterium.

Nodularin may be used as an analytical reference standard for the determination of the analyte in: surface and drinking waters by on-line solid phase extraction (SPE) and ultra high pressure liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) and Sediments and pore waters by accelerated solvent extraction (ASE) and HPLC-MS/MS.