The liquid chromatography-tandem mass spectrometry (LC-MS/MS) is the reference method for lipophilic toxins since July 2011. According to the European Commission EU 15/2011 this method has to be used as matter of routine, both for the purposes of official controls, at any stage of the food chain, and own-checks by food business operators. This legislation applies to European countries and any other exporting to Europe.
The presence of marine toxins in shellfish products could lead to fatal food poisoning. Monitoring programs to control levels of toxins establish monthly or even weekly sampling in production areas. Opening or closure of harvest areas would depend upon the results obtained. Post-harvest and end product testing is also carried out in some countries. Currently, paralytic (saxitoxins), ammesic (domoic acid) and lipophilic toxins (okadaic acid and derivatives, yessotoxins, pectenotoxins and azaspirazids) are legislated.
A recent study at the Northwest Fisheries Science Center has evaluated the application of screening assays for determination of DST
(diarrhetic shellish toxins) in shellfish. A lateral flow test, ELISA and PP2A tests were evaluated and compared with the standard regulatory LC-MS/MS (Eberhart et al, Marine Drugs, 2013).
Single Laboratory Validation of A Ready-to-Use Phosphatase Inhibition Assay for Detection of Okadaic Acid Toxins
OkaTest, based on a phosphatase inbhibition assay and manufactured by ZEU-INMUNOTEC, fulfils the Regulations (2074/2005 and 15/2011) requirements and can be used for detection of Okadaic Acid group toxins (OA, DTX1,DTX2, DTX3 including their esters).
PP2A (protein phosphatase) technique appears satisfactory for the analysis of DSP toxins in shellfish and is recommended as a rapid assay method for screening and end product testing.
This is one of the conclusions raised from a study carried out within the water project http://www.nppwater.com/index.php
Mussel samples from the biotoxins monitoring program carried by the Irish Marine Institute, Galway, were analysed. Samples were extracted from 3 sites (inner, middle and outer) from Killary Harbour, Ireland, in 2009 and 2010. Mussels from a DSP event were tested by Mouse Bioassay (MBA), ELISA (Abraxis), LC-MS and protein phosphatase PP2A assay (OkaTest).
ELISA kits showed matrix effects, but PP2A technique (OkaTest, ZEU-INMUNOTEC) was recommended as rapid assay.
More information on http://www.nppwater.com/data_access.php?id=85
Recently, two papers have been published in Talanta and Analitical Chimica Acta comparing protein phosphatases (PP) from several sources (ZEU-INMUNOTEC, Millipore and GTP) and origin (recombinant or natural).