Characterisation of okadaic acid related toxins by liquid chromatography coupled with mass spectrometry

In the Diarrhetic Shellfish Poisoning (DSP) phenomena, the parent toxins, namely okadaic acid (OA) and/or dinophysistoxin-2 (DTX2), are predominantly found esterified. Therefore, a toxicity assessment of a sample can only be performed after an alkaline hydrolysis step in order to recover the parent molecules in their free form. The presence of several OA diol esters has already been confirmed in Prorocentrum lima and Prorocentrum belizeanum cultures. This paper reports on the analysis of OA diol esters using liquid chromatography coupled with mass spectrometry (LC–MS/MS), and establishes a method for their detection and identification based upon their retention times (RT) and the fragmentation patterns of their mass spectra.