Development and validation of an accurate and sensitive LC-ESI-MS/MS method for the simultaneous determination of paralytic shellfish poisoning toxins in shellfish and tunicate

Abstract

An analytical method using liquid chromatography-tandem mass spectrometry has been developed for the determination of 5 paralytic shellfish poisoning (PSP) toxins (saxitoxin, gonyautoxin1-4) in shellfish and tunicate. The tested parameters included extraction solvent, clean-up method, mobile phase and mass spectrometric detection parameters including multiple reaction monitoring (MRM) conditions. The PSP toxins were extracted with 0.1 N hydrochloric acid and cleaned up using C18 SPE cartridges. Chromatographic separation of the 5 PSP toxins was carried out on a TSK-gel Amide-80 column with gradient elution. The developed method was validated according to the requirements of SANCO 12571/2013. The average recoveries of the PSP toxins ranged from 82.7% to 110.7%, the intra-day precisions were in the range of 0.3–10.9%, the inter-day precisions were in the range of 0.8–10.0% and the limits of quantification (LOQs) were in the range of 25–100 μg/kg, depending on the analytes and matrices. The validated method was successfully applied for the determination of 5 PSP toxins in real shellfish and tunicate samples, including mussel, oyster, ark shell, sea squirt and styela clava.