scope:

This document specifies a multireference method for the determination of lipophilic toxins (fat-soluble algal toxins produced by dinoflagellates) in shellfish and shellfish products by LC-MS/MS. This method has been validated in an interlaboratory study consisting of three parts via the analysis of both naturally contaminated homogenates and spiked extracts. For further information on the validation see Annex B.

The detection limit for DSP toxins, azaspiracids and pectenotoxins was determined to be 6 μg/kg shellfish meat and for yessotoxins 10 μg/kg shellfish meat.

Quantitative determination of okadaic acid, pectenotoxin2 (PTX2), azaspiracid1 (AZA1), and yessotoxin (YTX) can be carried out directly by means of standard substances available commercially. Assuming an equal response factor, okadaic acid is used for the indirect quantitative determination of the two dinophysis toxins dinophysis toxin-1 (DTX1) and dinophysis toxin-2 (DTX2); likewise azaspiracid1 (AZA1) is used for the indirect quantitative determination of azaspiracid2 (AZA2) and azaspiracid3 (AZA3), while YTX is used for homoyessotoxin, OH-yessotoxin and OH-homo-yessotoxin, and PTX2 for PTX1.

The limit of quantification for DSP toxins, azaspiracids and pectenotoxins was determined to be 20 μg/kg shellfish meat and for yessotoxins 35 μg/kg shellfish meat.

By means of hydrolysis, the esters of okadaic acid, DTX1 and DTX2 can also be determined quantitatively.