This European Standard specifies a multi-reference method for the determination of lipophilic algal toxins (fatsoluble
algal toxins produced by some dinoflagellates) in raw shellfish and shellfish products including cooked
shellfish, by liquid chromatography coupled to tandem mass spectrometry LC-MS/MS [1], [2], [3]. This method
has been validated in an inter-laboratory study consisting of three parts via the analysis of both naturally
contaminated homogenates of blue mussel and spiked extracts of blue mussel, oyster and clam. For further
information on the validation, see Annex A. Additional studies have investigated further matrices (see [4], [5]).
The detection limit for toxins of the okadaic acid group, azaspiracids and pectenotoxins was determined to be
6 microgram/kg shellfish meat and for yessotoxins 10 microgram/kg shellfish meat.
Quantitative determination of okadaic acid (OA), pectenotoxin-2 (PTX-2), azaspiracid-1 (AZA-1) 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
dinophysistoxins dinophysistoxin-1 (DTX-1) and dinophysistoxin-2 (DTX-2); likewise azaspiracid-1 (AZA-1) is
used for the indirect quantitative determination of azaspiracid-2 (AZA-2) and azaspiracid-3 (AZA-3), while YTX
is used for homo-yessotoxin, 45-OH-yessotoxin and 45-OH-homo-yessotoxin, and PTX-2 for pectenotoxin-1
(PTX-1).
The limit of quantification (LOQ) for toxins of the okadaic acid group, azaspiracids and pectenotoxins was
determined to be 20 microgram/kg shellfish meat and for yessotoxins 35 microgram/kg shellfish meat.
By means of hydrolysis [6], the esters of okadaic acid, DTX-1 and DTX-2 can also be determined
quantitatively as the corresponding free acids.