Preprint volume - SIBM

Pre-print Volume – Posters
PLANKTON COMMITEE
(Okadaic Acid, DTX1, PTX2) was performed using a Fusion stationary phase (100×2
mm, 1.8 μm) by Phenomenex (Torrance, CA, USA), while analysis of domoic acid in
samples extracts was instead performed on a 150×2 mm, 2.5 μm Phenomenex Gemini
reversed-phase stationary phase. Detection and quantification of toxins were performed
using an Agilent G1969A High Resolution Time of Flight Mass Spectrometer.
Analytes were identified automatically by means of the Data Analysis software Mass
Hunter. ®
Results – Total phytoplankton abundance varied between 1.0 to 5.0×10 6 cells l -1 .
Except for a sporadic occurrence of Noctiluca scintillans, among potentially HA, only
Dinophysis caudata, D. mitra and D. sacculus were recorded in the areas where the
influence of seawaters was the most direct. On the sea side of the Lido inlet (Venice
lagoon) the cell abundance of D. sacculus was 100 cells l -1 , but it decreased below 40
cells l -1 moving toward the lagoon waters and completely disappeared in the inner
stations, where the residence time and the water turbidity are generally higher. The
HPLC-MS determination highlighted the presence in trace of PTX2 molecule in cell
extracts collected at the Lido inlet. Due to the Dinophysis low abundance and PTX2
trace concentration, it was not possible to correlate the species occurrence with the
toxin. However, no other potentially HA was recorded in the site where PTX2 was
detected. In the Po Delta system lagoons, the results were quite similar, as Dinophysis
spp. were recorded only in seawaters, with abundances even lower (