Mass spectrometric detection and quantification of nodularin-R in flounder livers

Livers of flounders caught during August 1995 from the western Gulf of Finland and the Archipelago Sea were analyzed for nodularin-R (NODLN) by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and liquid chromatography-electrospray ionization-mass spectrometry (LC-MS). Results showed that NODLN was detected in samples by both MS techniques. NODLN content in samples varied between 0.082 and 0.637 microg g(-1) wet weight by LC-MS. Biotransformation products such as glutathione adduct were not found in the samples. The results showed that intact NODLN can be found in tissues after storage at -70 degrees C for several years.