Performance Characteristics of Refined LC-FLD and HILIC-MS/MS Methods for the Determination of Paralytic Shellfish Toxins in Shrimp, Whelk, and Crab

Background: Paralytic Shellfish Poison (PSP) toxins have been reported in non-bivalve shellfish species, including crustaceans and gastropods. Routine surveillance of these species is currently conducted in parts of England. To date, detection methods have not been validated for these matrices. Validation is required to ensure the test is fit for purpose, to give greater confidence in any results generated and ultimately facilitates accreditation.

Objective: The aim was to test and validate two independent PSP toxin detection methods previously validated for bivalve shellfish matrices, for applicability to commercial non-bivalve species of interest.

Methods: Matrices were shrimp (Crangon crangon), common whelk (Buccinum undatum), and edible crab (Cancer pagurus). The two methods assessed were the pre-column oxidation high-performance liquid chromatography-fluorescence detection AOAC 2005.06 Official Method of analysis and an internationally validated hydrophilic interaction chromatography-tandem mass spectrometry method. Brown and white crab meat were assessed separately.

Results: A refined extraction protocol was implemented with an increased solvent to sample ratio. The same extraction protocol was utilized for both methods, allowing both methods to be run simultaneously. Method sensitivity, recovery, repeatability, and method uncertainty were characterized in all matrix/toxin combinations. Overall, both methods performed similarly to that previously reported in bivalve mollusks. Acceptability of the majority of toxin/matrix combinations was evidenced through comparison of method performance characteristics against specific performance criteria, including Horwitz ratio values.

Conclusions: Both PSP toxin detection methods were found to provide acceptable performance for the monitoring of shrimp, whelk, and crab species.

Highlights: Two PSP toxin detection methods have been single-laboratory validated successfully for three non-bivalve shellfish species.